Standardize [color=ARG] to lower-case to avoid incorrect transaparency handling
fix 'transparent => inline-spoiler' feature did not have same click behaviour as just inline-spoilers
Inline-spoiler no longer prevents rendering of text color on hover, yet 'transparent' color is over-riden when using the transparent color => inline-spoiler feature
Support [tab=id]text[/tab] to link tab ids
Fix slide & slide header support only supporting legacy multi-options format, and not XF2.1+ native
Implement XF2.2 style bb-code arguments for accordion/slider/tabs slides
Ensure align/align_title bb-code option for title alignment is consistently supported for accordion/bimg/encadre/slider/tabs
Update bb-code description for hr/accordion/bimg/encadre/fieldset/slider/tabs, this overwrites the bb-code definition!
Add explicit support for bb-code pages being considered "staff" for staff-only bb-codes. This also refactors how content is considered "staff" to be easier for other add-ons to extend.