reports: BaseODS puts each line of strings in a P tag.

This seems to be the most straightforward way to get Calc to automatically
determine a nice row height for multi-line string cells. This has become a
lot more noticeable now that query-report supports putting postal addresses
in cells.

fund: Bugfix crash when text report has an empty balance.

This mostly happens when a date range includes the opening or closing of a
fund account, because then the reported beginning/ending balance is empty.

fund: Add totals rows to the full report.

This is easy to do with the current infrastructure, and it's nice to have.

fund: Use Balances instead of PeriodPostings.

A few motivations for this:

* This makes the fund report more maintainable, because the data structure
is better suited to the task at hand, making it easier to follow what's
going on.

* This helps put Balances through a little more testing with a high-level
report.

* This makes the fund report a little faster, since totals are usually
calculated from a smaller number of Balance objects rather than all
Postings over a period.

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.

cliutil: Add ReturnFlag.

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

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.

fund: Split ODS into two sheets.

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

tests: Extend fund report input.

This lays the groundwork to test both the opening balances generator,
and additional account breakdowns on the fund report.