extract_odf_links: Make "not found" warning easier to parse.

e.g., you can just use `grep | cut -b N-`.

extract_odf_links: Support multiprocessing.

This cuts audit packet manifest build time in half on my 8-core laptop.

reports: All reports support rewrite rules.

I realized that if ledger-report supported rewrite rules, then it would
include all the information necessary to reproduce the numbers on the
statement of functional expenses.

With that, it was easy enough to add support to the rest of the reports for
consistency's sake.

rtutil: Fix crash when multiple RTLinkCaches race.

This was most likely to happen with multiple bean-checks running in
parallel: they would both see a new RT URL, fetch it, and try to
insert it into the cache. That's not a problem as long as they're
both inserting the same URL, so catch that exception.

extract_odf_links: Add --relative-to option.

This is just too convenient for our usual case where we expect
all links to be relative to a specific directory (the repository).

balance_sheet: Remove custom data normalizations.

These can be supported with rewrite rules now.

rewrite: New module.

This module is intended to make bulk data changes to normalize
information across FYs for reporting.

ledger: Formatting modernizations.

* Equity sheet(s) report project.
* Headers include account classification.
* Bottom lines are formatted in the usual accounting way.

fund: Text output readability improvements.

Make it look more like the spreadsheets:

* Don't normalize Expenses negative.

* Consistent account order: Income, then Expenses, then Equity.

* Include a bottom line divider for each fund.

fund: Incorporate Equity accounts into Release from Restrictions.

This matches what we do on our Statement of Activities in the
balance sheet report.

meta_expense_type: Refine defaults.

* Default "management" for more accounts.

* There's a good handful of accounts where in past audits, the functional
split has been "Conservancy expenses are management, project expenses are
program." Handle those cases too.

balance_sheet: Re-simplify the "release from restrictions" math.

Basically the original bug was an incorrect sign. The last implementation
was very belt-and-suspenders to help me think through it. But it's also more
error-prone in the long run.

balance_sheet: Correct "release from restrictions" calculation.

The old version was causing Income:Donations:Released postings to be
"double-released." This version gets the bottom line numbers for
Net Assets With/out Donor Restrictions match the corresponding numbers
in the fund report.

balance_sheet: Support arbitrary date ranges.

This lets you do year-over-year comparisons of smaller ranges of time, like
a quarter.

balance_sheet: Sort trial balance accounts.

They were previously sorted by date, then name, which is slightly less
helpful.

balance_sheet: Transform "chart of accounts" into trial balances.

It was mostly this already, just needed to add a column and change the
title.

balance_sheet: Balance.total() accepts multiple account names.

This simplifies the code to total all equity.

balance_sheet: Balance only considers post_type for Expenses.

This simplifies the code and slightly optimizes it, since now Balance
won't store and keep re-summing income-type breakdowns that nothing
needs.

balance_sheet: Default classification sort by root account.

This provides more consistent presentation across sheets,
especially the financial position+cash flows.

balance_sheet: Add cash flows report.

With this, the balance sheet report has all the reports from the audit.

meta_tax_implication: Update values for TY2020 1099-MISC changes.

Support the new 1099-NEC form.

expense_type: Revamp expense-allocation metadata.

* Change the name for symmetry with income-type.
* Standardize on "management" value because that's what it's called in the 990.

cliutil: Add ReturnFlag.

Take this opportunity to re-standardize flag values now that it's clear
what's most common.

ledger: Add transaction-level reports.

Mainly for the cash disbursements and receipts reports, which have dedicated
shortcuts.

ledger: Prepare LedgerODS for subclasses.

This commit reorganized the class internals to make it more straightforward
to add a transaction-oriented reporting subclass.

accrual: Restore "since last nonzero" behavior to outgoing report.

Basically this behavior is an extension of the fact that the outgoing report
is grouped by RT ticket rather than "accrual data." Ripping this
functionality out of other reports was correct, but it needed to stay for
the outgoing report.

ledger: Only display accounts requested with --account.

Now that we're accepting classifications, it's possible to specify account
options that select some but not all accounts at the same level of the
hierarchy. This commit tracks requested account names separately from sheet
names to do that correctly.

ledger: Add memo column to Income sheets.

Quick accommodation for project reporting.

books: Loader.load_none() returns default options_map.

This way it's still safe to assume all the expected keys are there.

ledger: --account accepts a classification.

This makes it easier for users to specify a group of accounts.

data: Add Account.is_account and Account.load_options_map.

These work in concert to distinguish account names from other
colon-separated strings.

ledger: Include all fund accounts in default project ledger reports.

This brings the reporting into sync with the fund report.

fund: Swap Unearned Income and Payable columns.

Unearned Income is more interesting.

fund: Add bottom line totals to Fund Report. RT#4582.

This required keeping the balances from write_row, and then a lot of other
changes followed from that. In particular it makes more sense to build the
fund report sheet from scratch rather than copying the breakdowns report and
chiseling the fund report out of it.

accruals: Aging report shows all unpaid accruals color coded by age.

Some readers care about recent accruals, some don't. This presentation
accommmodates both audiences, providing the data while making it easy to
ignore or filter out recent accruals.

accrual: Rip out unnecessary functionality.

Now that make_consistent is really robust, there's much less need to do all
the consistency checking that was done in AccrualPostings.__init__. I expect
this will provide a performance benefit for large reports, since we'll be
calculating data for many fewer accrual groups. The only performance penalty
I see is that the aging report has to calculate the balance three times for
each row it reports, twice in write() and once in write_row(), but that
seems okay and can be cached separately if needed.

accrual: AccrualPostings.make_consistent() groups accruals by date.

This accommodates cases of contracts without separate invoices,
where a series of payments are scheduled over time.

The dance we used to do of group-by-invoice, then make consistent was
already suspect. It was originally motivated by the consistency checks that
are now gone. Use this opportunity to clean up and just make make_consistent
a classmethod.

fund: ODS report usability improvements.

* Lock the first column.
* Open the breakdown sheet by default.

reports: Remove BaseODS.style_dividerline.

Obsoleted by the new border_style() method.

fund: Split ODS into two sheets.

The first only has equity numbers the auditors look at.
The second includes balances of additional accounts.