The behavior is not entirely idempotent (most notably for
buildconfig.html), but this can be improved later if necessary.
It is idempotent where it matters.
This allows to get rid of config/makefiles/rcs.mk and its uses.
See the revisions a few steps prior for more fine-grained information. This just
needs to be relanded because our automation doesn't like non-ASCII commit
messages.
--HG--
extra : amend_source : 0ee4e0da1ea9ada815abfe989c51030db24aac56
CLOSED TREE
Backed out changeset 28abb8af2d62 (bug 1099430)
Backed out changeset 358aa39360d5 (bug 1099430)
Backed out changeset 3313e545f4f6 (bug 1099430)
With these substitutions, it is possible to have comm-central's versions of
these files merely include the mozilla-central versions and avoid having to port
small changes to these files.
