rose_prune: user interface refresh.

Functionalities now divided into 4 settings:
* prune-remote-logs-at=cycle ...
* archive-logs-at=cycle ...
* prune-work-at=cycle[:globs] ...
* prune-datac-at=cycle[:globs] ...

The 1st two functionalities call the underlying libraries of `rose
suite-log` to re-sync the remote job logs, prune them from the remote
hosts, (and archive the cycle job logs).

The last two functionalities are to prune items in the work directories
and the share cycle data directories. Globs can be specified for each
cycle so that only matched items in the relevant directories are
pruned.
rose suite-log: source.html: fix undef suite title

Title was displayed as undefined. Now use an AJAX call to load the main
JSON file to obtain the information. This should be more robust than
having to rely on it being parsed as an argument from index.html.
rose suite-run: fix already running bad error.

Was returning a `IndexError: list index out of range`. Should be fixed
by this change.
rose suite-run: improve already running message.

Print "detected PORT-FILE-PATH".
t: rose_prune: now passes reliably.

Ordering of JSON files and dot files were making things unreliable
previously.
Merge pull request #787 from matthewrmshin/fix.rose-suite-log.source

rose suite-log: source.html: fix undef suite title
Merge pull request #788 from matthewrmshin/fix.rose-suite-run.already-running

rose suite-run: fix already running bad error.
Merge branch 'master' into rose_prune
rose_prune documentation: fix typos.
Merge pull request #789 from matthewrmshin/rose_prune

rose_prune: user interface refresh.
Merge branch 'master' of github.com:metomi/rose into gh-pages