Corrected email event handler command help.
Added suite.tex to the Makefile.
New submit and submit-fail task triggers.
Tidied event handler arguments.

Undid replacement of space with underscore in event names; added a
couple of missing message arguments; improved the message arguments.
New comprehensive task events test suite.
Restore the old "extra log files" functionality to gcylc.

Supports extra user-specified log files in the task log viewer.
Make gcylc suite and task log view windows consistent.
Merge branch 'master' into 469.event-hooks-revisted
Merge branch 'master' into 469.event-hooks-revisted

Conflicts:
	lib/cylc/task_types/task.py
Remove 'execution' prefix from run-db events.
Restored extra log files, again.
Fix for merge of job poll and kill changes.
Merge pull request #477 from hjoliver/469.event-hooks-revisted

469.event hooks revisited