The MobileFrontend section numbers that were used here only count
top-level sections, but this value was passed to code in
MobileFrontend's TalkSectionOverlay#onSaveClick, which uses an API
expecting the standard MediaWiki section numbers.
Extract the section number from the section edit link, like we do
in mobile.init/editor.js in MobileFrontend.
Also, disable the special talk page view unless we're viewing the
latest revision of the page. That could also lead to posting in the
wrong section, as sections are often added and removed, which changes
the numbers.
Bug: T252828
Change-Id: I553a508658804dd8672f2268b7118f77458a9dba
Additional changes:
* Address a fixme relating to the overflow icon and move some AMC styles
out of the critical path for non-AMC pages
Note about ellipsis:
The class mf-mw-ui-icon-rotate-clockwise cannot be used as it's part of
MobileFrontend and loaded via JS. Minerva must work without MobileFrontend
and this rotation is needed without JS.
Bug: T244444
Change-Id: Ifd02c50305cf036dd6df640d778678668507e5eb