Job submission retries, and new submit-failed state.

Submission failed event hook works too (it didn't before!).
gcylc config and themes changes...

The new submit-failed state required *another* task state color, so:
 1) new default theme with a better separation of colors
 2) backward compatibility: don't abort if a custom theme is loaded
    that does not define the new state color.
Removed obsolete task state check functions.
Made failed a bluer shade of red.
Merge branch 'master' into 215-job-submission-retry
Better run db events for job submission.
Added missing example suite bin script.
Removed unused code from gcylc config processing.
Manual reset to "submit failed" not currently allowed.
Merge branch 'master' into 215-job-submission-retry
Updated gcylc color themes a bit.
Task event recording rationalization.
Updated host record in db events table.
Disable interactive command prompts via site/user config.

Closes #373.
Update -f/--force command option help.
A cleaner way of removing -f from commands that do not prompt.
Make out of order messages work.

Don't update elapsed time after task completion if no started message
was ever received. Complete any remaining outputs if a succeeded message
comes in. This closes #351.
Put true event time in task messages; closes #380.
Background task started and internal messages.

Closes #192. Not backgrounding task succeeded and failed messages
because there's no point(?)
(Removed a test print statement)