Bug 1094560 - Eliminate the clone of config/recurse.mk in comm-central, r=glandium, a=jcranmer

Ideally, this file would just die altogether. However, MOZILLA_DIR presently
gets defined in m-c only as late as rules.mk (included via this file), so it
requires bigger disruption to the m-c build system to do it. So instead, the
copy in comm-central is just plain emasculated.

Included are some ports of older build config bugs that are needed to make the
current m-c copy actually usable from c-c. Another change directly ports bug
1094033.