More CRM cleanup

In this PR:

- Code cleanup for consistency. (I know we're not using the PEP8 convention for hanging indentations. Any changes for w.r.t. that can be done with #730.)
- Gets rid of a bit of dead code, and some outdated conventions.
- Converts a couple more CBVs.
- Adds the remaining tests for all views, with the exception of the timesheet views. (I am currently working on an updated timesheet and expect to fully update the tests with that work.)

Apologies for the bulk of this PR. The commits should be fairly readable anyway. I believe it to be the last of the work I'd started to clean up the CRM app before starting on the new timesheet.