Universal task state and name filtering for gcylc.

Via the shared updater rather than tree/list model filtering.
Improved dot updater task_list construction.
Added gcylc tool bar transpose buttons.
Addressed review comments.

Toggle button for graph transpose.
Changed dot view default transposition.
Changed graph view menu item name.
Fixed a doc typo.
Graph view: remove only filtered-out nodes.
Dump loaded suite configs to the log dir.
Added a test for suite config logging.
Write cylc version to the suiterc log.
A display-once option for the monitor command.
Some style corrections.
Merge pull request #1272 from hjoliver/1217.log-loaded-configs

Dump loaded suite configs to the log dir.
Merge pull request #1273 from hjoliver/monitor-cmd.oneoff

A display-once option for the monitor command.
Merge pull request #1253 from hjoliver/gcylc.universal-filter

Universal task state and name filtering for gcylc.