(bug 42398) Kill ve.ce.Meta{Block,Inline}Node, not needed.

CE doesn't actually render meta nodes anymore now that we split them out
into the meta-linmod.

I took a stab at consolidating metaBlock and metaInline (into simply
'meta'), but we can't do that with the current node API unless we put a
lot of meta-specific hacks in the converter. So I'm leaving this for the
node API rewrite.

Change-Id: Ie83413df718eabcaeb504316a2db0d24a1be2226