Fixes #1808: use different treeStableTimer in AnyBranchScheduler for different sources
add buildrequests filtering by branch and project

Change-Id: I6b865a565a2bfc68be32e86f2e0d2172d768a60c
fix example
SVN: Add option to use 'last chnaged' revision rather than global revision
BuildslaveChoiceParameter and EnforceChosenSlave: force scheduler hooks for explicit slave control
enforceChosenSlave: address review comments
add warning about LoopingCall and TimerService; refs #1038
Merge branch 'BuildslaveChoiceParameter' of git://github.com/jaredgrubb/buildbot
Merge branch 'treeStableTimer' of git://github.com/jaredgrubb/buildbot
Merge branch 'SvnLastChangedRev' of git://github.com/jaredgrubb/buildbot
Merge branch 'et_scheduler_local_max' of git://github.com/jgonzalezmendez/buildbot