Show git branch in version output. fixes #1953
Also make sure strings in _version.py are correctly escaped, and repair a test.

Signed-off-by: Daira Hopwood <david-sarah@jacaranda.org>
docs/proposed/leasedb.rst: Add design doc for leasedb.
This version refs #1834.

Signed-off-by: David-Sarah Hopwood <david-sarah@jacaranda.org>
Update terminology in RAIC design doc.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>