Use mw-ui-anchor and mw-ui-button from Core

Change-Id: Ia77951388d46ec09d26878f355a13028f54e3c6f
(cherry picked from commit 1f62d2c2acc8ff3e1350a66d2964efbbc1e6b493)
Remove mw-ui-active and change subscribe button inversion

Change-Id: I4ede8b216c5ab475b2674a32712a8ee8fc920941
(cherry picked from commit 7af69eac5d2675b6e46f4af721414f4638a016a8)
Merge "Remove mw-ui-active and change subscribe button inversion" into wmf/1.24wmf16