FreeSWITCH-FS-7269

FreeSWITCH: Fix underlinking of applications (partial brown paperbag cover-up)

OK, libtool pulling in all depdencies doesn't work (*sigh*)
so add CORE_LIBS back to _LDADD and also add ODBC_LIB_FLAGS (conditionally).

Tested on Debian Squeeze (6.0.x) amd64 (libtool-2.2.6), where
everything seems to be falling apart easily.

There's still a lot of room for improvement, though. Bundled libs are making
this harder, as we don't have a sane way to get their dependency libs and
libtool drops them on the floor, even if they are in the .la-file's dependency
list (e.g. mod_spandsp using libtiff(.la), which needs libjpeg).

( reference: http://www.gnu.org/s/hello/manual/libtool/Inter_002dlibrary-dependencies.html ).

Let's see what i did break this time...

Signed-off-by: Stefan Knoblich <stkn@openisdn.net>