Simplified filtering of terms
Filtering of terms supported by teccc_ignore_slug() tpl tag/wrapper func.

Colors now stored in a different structure that retains the memory of the setting even if it is later ignored.

Plus, some groundwork for i18n/l10n.
Merge branch 'experimental' of https://github.com/barryhughes/events-calendar-category-colors into barryhughes-experimental

Conflicts:
	classes/categorycolors.php