extend Rmdir operation's timeout

The old timeout value is 120 seconds, which sounds pretty enough for
normal directory removal. But not for our 25GB codebase, so I extends
the limit to 10 minutes.
p4 sync now syncs from p4base instead of p4stream, the stream is regulated by clientspec
Merge branch 'master' of https://github.com/jonnyyu/buildbot

Conflicts:
	slave/buildslave/commands/fs.py