Tidied user guide information on log directory location.

(now determined by site/user config files)
Removed some obsolete cruft and doc on "cylc diff".
A site/user config reference section for the User Guide.
Tidied the new MI implementation further.

And fixed a bug introduced into it yesterday: closes #320.
Removed useless single-task validation complication.
Avoid bash-specific test syntax in Makefile.
Merge pull request #323 from hjoliver/sh-compat-makefile

Avoid bash-specific test syntax in Makefile.
Merge pull request #322 from hjoliver/320-bug-fix-MI-again

Tidied the new MI implementation further.
Updated User Guide installation section.

For Fedora 18 package manager.
Updated change log.
Closes #324 - visualization settings being ignored.

This was caused by the recent task ID delimiter change from '%' to '.'.
The new delimiter has to be escaped for use in regular expressions.
Also fixed a couple of other instances of this problem.
Fixed a typo in the little-used depend command.
Merge pull request #325 from hjoliver/324-fix-visualization-settings

Closes #324 - visualization settings being ignored.