Fix 2 function docblock headings by dispatching them from the originally single metabox function docblock.
Also add version tags to the 2 metaboxes split off @since 2.2.0.
* Displays all options for the footnotes start and end tag short codes. (Initially called “Footnotes styling”.)
* Displays all options for the footnotes numbering. (Newly individualized.)
* Displays all options for the scrolling behavior. (Totally new as scroll offset and duration were initially hard-coded in the template.)
(This is part of WP coding standard compliance.)