Upgrade "cylc trigger" functionality.
State dump once before multiple task manual trigger.
Remove manual trigger flag reset in task.py
Cleaned up crappy queue limit coding (mine).

(previously got right result, but was unnecessarily perverse)
Recoded queue limiting logic from scratch.
Merge pull request #706 from hjoliver/703-trigger-now-mod

703 trigger now mod
Merge branch 'master' into cug-new-tutorial

Conflicts:
	lib/cylc/task_pool.py