InlineEdit: Add GET /changes/{id}/edit/{path}/type endpoint

Change-Id: I3b5bb2fab294e5ba560ac2db32dcc80055bdc6a8
Add REST API to retrieve file's content type from revision

Change-Id: I0435893cc7cdc0a69f88bb61efccb34593333e1a
Also export zero-scores to Prolog

Zero scores can provide information, so also export them to Prolog rules.
(I.e. it might be interesting if the default score has been changed or
if you want to check if all users have provided a score.)

Bug: Issue 2741
Change-Id: Ie5b7ec67214e3a98ad3fa07b9bd3d45bc8cfdb89
Update doc build and project site sections of release documentation

Add section headers for the documentation build and project site
update sections.

Reword the documentation build section to make a bit more sense. The
command to build the documentation should be mentioned before the bit
about how to upload it.

Change-Id: Ica473dda5e74726a297918a002de1a62ae8de0d1
Merge "Also export zero-scores to Prolog"
Move GetChange#cache to a better-named Response static factory

The old method wasn't telling the client to not cache per se, but
instead to use the cached version after revalidation. "Cache" was
sufficiently generic to be confusing.

Move this to a factory method in Response, and give it the slightly
more descriptive name withMustRevalidate.

Change-Id: Ic0bf486637f4542de3a2e6088eff1fee2d26c0d7
Mention the version.py tool in the release documentation

Change-Id: I7448d89a4239a1e584ce82c12f701f6ff83227e4
Merge changes from topic 'inline-3'

* changes:
  Add REST API to retrieve file's content type from revision
  InlineEdit: Add GET /changes/{id}/edit/{path}/type endpoint
Merge "Mention the version.py tool in the release documentation"