initial master side P4() source step
removed defaultBranch argument which has no purpose. Improved API docs. Added P4:.. prefixing on logging.
added docs for P4 master side source step
address jaredgrubb's pull feedback
Add latent buildslave for OpenStack

The buildslave has limited functionality for interacting with
OpenStack's Nova component. Booting and terminating instances
works correctly, but no interfacing with the network part.
remove possible_methods per pull request comment since it doesn't really apply to perforce
Merge branch 'master' of https://github.com/buildbot/buildbot into p4_master_step_2012
Move buildslave.py into buildbot.buildslave
Move openstackbuildslave.py into buildbot.buildslave.openstack
Fix indentation
Typos: possibilty, prefined, builtbot, explictly
Fix LibVirtSlave example and add connection argument description to docs
Ticket #2409
Using DeferredLock.run() in favor of .acquire and .release
in master/buildbot/process/buildrequestdistributor.py
Add blurb in release notes
Add documentation on how to use new Openstack latent slave
Upgrade tests for 0.8.7
Fix to ticket #2310: make loadConfig check for a configfile path in the .tac file if the default location doesn't exist
Add a test that getting the config file path from the .tac file works
Merge branch 'typos' of git://github.com/vrutsky/buildbot
Merge branch 'libvirt_slave_docs_fix' of git://github.com/vrutsky/buildbot