Vim control lines were re-introduced or not entirely cleaned up.
This nukes them again.
Removing from embedding, extensions, gfx, hal, ipc, layout, mailnews,
media and memory. More to come.
To better distinguish the calculation of line height (still present with args)
and simply getting the line height without args, it's now called GetLineHeight()
This also introduces `mLineHeight` to cache specifically calculated line heights
that aren't "auto" (which is a magic value), and it opens up the possibility to
override it in Part 7.
Moonchild
Mats Palmgren
Matt A. Tobin