add build.buildid, sl.buildslaveid, and st.stepid

This required a lot of refactoring of old tests.  It also required
changing the automatic generation of source step names to generate
proper identifiers.
restore 'gerritchangesource: use gerrit's changeid as the branch' (ccf6c117)
add buildbot.util.asyncSleep
Add an integration test for try scheduler client/server interactions.

This runs a full master with real builds.

Waiting for SSH builds does not work - the buildmaster returns buildset
ID's, while the client expects its external_idstring, so it waits
forever.  This functionality will be difficult to support as-is in nine,
so it's been removed.
Merge branch 'restore-gerrit-changeid-in-branch' of git://github.com/djmitche/buildbot (PR #1024)
Merge remote-tracking branch 'origin/8/try-integration-test' (PR #1026)

+autopep8
Merge branch 'master' into nine

Conflicts:
	master/buildbot/clients/tryclient.py
	master/buildbot/schedulers/trysched.py
	master/buildbot/test/unit/test_util.py
	master/buildbot/util/__init__.py
fix use of nonexistent getBuildsForRequest
Minor fixes to try scheduler and its integration tests
skip test_try_client integration tests if buildbot-www isn't installed
Merge branch '9/buildid-stepid-buildslaveid' of git://github.com/djmitche/buildbot into nine (PR #1018)

I re-addd status.build_started so that the try scheduler tests would
still work.
All resource types are now implemented, including buildrequests
buildbotService: rework, for better event support

New api simplifies a lot the common use cases of the controllers:
bind() now registers to 'update' events on all element of the list
e.g:
sse/add/aa4514dc-adae-4b2e-8c1f-d5037574821f/builder/2/build/*/new
sse/add/aa4514dc-adae-4b2e-8c1f-d5037574821f/builder/2/build/*/change

bind() now takes a onchild callback, which will be called at init time, and also
at event time when new child are happening. This help to populate subchilds.

See doc for more info on the new api.

+ bump up a few versions
+ re-enable coffeelint, and fix the remaining errors
+ some new pages
buildbotService: reuse of bound data

see doc change.

The goal of this commit is to enable much faster
user experience by doing more internal caching

Signed-off-by: Pierre Tardy <pierre.tardy@intel.com>