Repair menu highlighting, both for main menu and submenus

During the recent improvements made on the website, the menus and
submenu highlighting for selected menus fell into disarray.
Correction requires changes to the CSS and templates both, because
Django doesn't really have a convenient way to set variables in
templates to use to solve this.

There are still a few submenu items highlighting not working even
after this commit. More work needs to be done.

Rename "supporter" to "sustainer" in templates and URLs.

Does not rename the models.

Copyleft Compliance: rewrite about page in light of strategic plan

The copyleft-compliance/about.html page doubles as the introduction
page to our compliance work. This is a start at the rewrite of that
page to link off to the new items and have new text to inspire
interest in the project.

Anchor for Compliance Program for Linux Developers

I think I'd already linked to this elsewhere even and forgot to add it.

Add links to template agreements.

But encourage people not to sign them.

Add paragraph about principles-discuss.

Welcome those who visit this page to join the principles-discuss mailing
list. In doing so, also make a link to the principles themselves.

Rename Members->Projects in menu navigation et al

Due to confusion about "members" and "supporters", we want at least the
menu navigation to not use the phrase "members" since some Supporters
expect that to refer to a type of donor.

While we will not be rebranding "member projects" fully at this time, we
want to favor the term projects.

A few additional changes, in particular moving files from members/ ->
projects/ directory will be needed in next commit.

Rework text about reporting violations.

Include a link to my blog and how it's temporary.

Make section heading about donating.

Rewrite page; fully discuss all compliance effort

This about page now talks about all of Conservancy's compliance efforts.