Don't claim to obfuscate passwords with master-side source step.

We don't currently have any way of obfuscating arbitrary things sent from the
master, so don't claim that we can.
Add a link to Interpolate in multi-codebase documentation.
Merge pull request #604 from tomprince/doc-improvment

Add a link to Interpolate in multi-codebase documentation.
Merge branch 't2421-trial-jobs' of git://github.com/iffy/buildbot
fix pyflakes
Merge branch 'master' of github.com:buildbot/buildbot
Builds on language environment patch from Alice for ticket 2419
Fixed try builds not being scheduled when more than one is pending
Merge branch 'buildbot-0.8.7'
run the master for a split second in integration tests
Merge remote-tracking branch 'lorentz/master'
RemoteCommand: Fix handling of collectStderr.

This argument has never worked, since it was added, but it wouldn't
fail unless something was actually received on stderr.
Add some better debugging for buildstep test failures.
As per irc discussion with tomprince, wrapped 'getElementsByTagName' in
try and added code for storing in Step log file. Addresses log.err issue
in pull request comment
Monkey patch recent gatherResults on old versions of twisted.

Newer versions of gatherResults support consumeErrors, which we would like to use.
Merge branch 'gatherResults'
- Changed graceful to clean.  Added also some docs.
Handle slave disconnections during build start better

This:
 - checks for a slave disconnection at the last possible moment
 - handles exceptions from startBuild's deferred better
 - treats errors in startBuild as EXCEPTION, not FAILURE

Fixes #2427.
Partial Test changes for 2419fix
comment about maybeDeferred use; better log.err message