metomi/rose#733: testing - fix null path tree menu
metomi/rose#733: dedicated example suite
metomi/rose#733: tidy
metomi/rose#733: file
metomi/rose#733: make sub-text sensitive for latent and ignored variables
rose slv: new CLI. Support view and update modes.

In update mode, arguments can now be a `*` (for all task jobs), a cycle
time or a task ID.

Support a `--tidy-remote` option to remove job logs on remote hosts
after their retrieval.

Support a `--archive` option (and removed
`--log-archive-threshold=CYCLE`) to switch on archive mode on the
specified cycle times in the argument list.

Switch off view mode by default in update mode, but can be turned on
explicitly with `--view`.

Some internal logic improvements.
rose suite-hook and slv: logic fixes.
rose slv: plug more gaps for getting task job hosts.
rose slv: minor fix to comments and interfaces.
rose suite-restart: = `rose suite-run --restart`
Merge pull request #740 from matthewrmshin/rose-suite-restart

rose suite-restart: = `rose suite-run --restart`
Merge branch 'master' into rose-slv-syntax
rose.run: use port file to check for running suite.

Only use `cylc ping` for reload or in install-only mode.
rose slv: handle negative year.
rose suite-log: replace `rose suite-log-view`.
rose suite-run: fix logic.
Update CHANGES.md
metomi/rose#733: adjust nav panel hover-over
rose.run: refactor.

Separate rose.run into rose.app_run, rose.suite_run and rose.task_run.
metomi/rose#733: fix test metadata