WITH_META_MODE: Mitigate switching from without to with META_MODE.

Adding .META to targets-to-build will ensure that they will rebuild if there
is no .meta file.

Adding it to all SUFFIXES and objects ensures that at least objects will
rebuild if there is no .meta file.

This will be reverted if bmake's behavior changes to rebuild on missing .meta
files.

Sponsored by: EMC / Isilon Storage Division