Update VisualEditor for cherry-picks

New changes:
858d56e Update VE core for cherry-picks
    9e62c49 Restore original rowspan/colspan rather than normalizing or overwriting with NaN
    ebe5e36 Initialize mobile context as visible

Change-Id: If4f9358ababb149c83e1921ce0ec4328da5049d6
Merge "Update VisualEditor for cherry-picks" into wmf/1.25wmf8