Both of these survived across many rewrites, I tracked down the
original commits that added them:
* footer.less: Added in 6d5dca5a899d45512c1031c4235f26cc755b933b in
MediaWiki core (rSVN62030) as a workaround for "weirdness" in IE 7.
Users of IE 7 experience much worse weirdnesses when viewing pages
these days.
* tabs.less: Added in 299d1f328c2ad1475c8a1ac19b4fa07fc087d239 in
MediaWiki core (rSVN53247) under a generic label of "RTL fixes".
After change 5d0a07bf9d this is
actually a no-op.
Change-Id: Iac3d2a26438226a3e23e067780c4b2810ac4903f