tests for assertArgspecMatches
fix assertArgSpecMatches to function as documented
fix addBuildset, and its test coverage
added deferredpool and tests. Doesn't have terrycojones tests yet.
pulled in from https://github.com/terrycojones/txrdq/tree/b6e45003
make the trigger steps's fake scheduler behave like the real one
Merge branch 'buck-nine-fix-assertArgSpecMatches' of git://github.com/bukzor/buildbot into nine
Merge branch 'buck-nine-fix-addBuildset' of git://github.com/bukzor/buildbot into nine
remove tabs
Merge branch 'buck-nine-deferred-pool' of git://github.com/bukzor/buildbot into nine

(with attribution to Terry Jones in deferredpool.py)
Merge branch 'buck-nine-fix-trigger-step-fake' of git://github.com/bukzor/buildbot into nine