Support foundationwiki.

OCG is enabled on foundationwiki, so it would be good if Parsoid supported
it!

Note that wgRawHtml is turned on on foundationwiki, though, so not all
pages will probably parse correctly.

Change-Id: I7e0e1471019caa2f2d95d3d17d5628e9ff529ffd
Merge "Support foundationwiki."