Increase unittest coverage for getChangesForBuild
Fix bugs raise by the unittests when several codebases are used.
fix api_proxy

Now that we have nine.buildbot.net, we can use api_proxy to debug the UI
based on real data

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>
more review addressing
fix nonfunctional test case
Fix off-by-one error in log chunk handling

The extra `- 1` here caused single blank lines to be skipped when
chopping un-requested lines of the end of a response.  Earlier tests,
even if they had actually been running, would not have discovered this
as they did not test blank lines.  Fixes #3101.
Fix benallard's comment
Add changes for new branches in GitPoller

With the new branches=True argument for GitPoller to watch all
branches, _process_changes() does nothing if a new branch is pushed. The
only time it adds changes to the database is when a new commit is pushed
on an existing branch. This is unfortunate because this means in order
to have buildbot build all git branches, one must first push the branch,
wait for GitPoller to detect it, and then push new commits on the
branch.

http://trac.buildbot.net/ticket/2837
Print detailed information if _dovccmd() in GitPoller fails

Otherwise the outputted information often isn't sufficient to debug the
problem.
Exclude all commits we already know about
Store revs in ascii strings, not unicode.

This is to avoid Twisted complaining about unicode arguments being
passed to reactor.spawnProcess.

Also: release notes

Conflicts:
	master/buildbot/changes/gitpoller.py
Merge pull request #1433 from delanne/gitpoller-do-new-branches

Gitpoller do new branches
Merge pull request #1436 from djmitche/bug3101

Fix off-by-one error in log handling of blank lines
Merge pull request #1427 from tardyp/apiproxy

fix api_proxy
Merge pull request #1429 from delanne/FixBug_getChangesForBuild

Fix bug get changes for build
make the category param of gitpoller callable.
give the whole changeDict
WIP: Add a unittest