* Check that the C++, Fortran 77, and Objective C comilers emit code
that can link against object files emitted by the C compiler.
Moves some built / run time errors to configure time, which is
nice and should help with the debugging
* Remove unneeded -F option when building the XGrid components,
which started causing problems with LT 2.0.
* Try to use the XGridFoundation library, rather than just seeing
if we can give -framework XGridFoundation. Should make the
test slightly more accurate
* Don't assume XGrid is unavailable on 64 bit platforms, as that
won't be true on Leopard
* Require AM 1.10 or newer if using AC 2.60 or newer, so that
we don't have a split of AC supporting Objective C and AM
not doing so
This commit was SVN r12701.
