--enable-backends/overlays override individual settings

[Hallvard B Furuseth <h.b.furuseth@usit.uio.no>]

./configure --enable-backends enables sql even with --disable-sql.
--disable-backends has no effect (just means don't enable all backends).
The same goes for --enable-overlays.

Unless someone protests, I'll let --<enable/disable>-<backends/overlays>
provides the default for all backends/overlays instead.
Thus --disable-sql above will work, and --disable-backends disables all
backends that are not explicitly --enabled.

Patch: <http://folk.uio.no/hbf/OpenLDAP/enable.patch>.

-- 
Hallvard
For sale: Parachute. Never opened, used once, slightly stained.