[Bug-glpk] Patch for glpk 4.34

[Benoit Dupont de Dinechin]

This simple patch enables building and checking out of the source tree as in:

mkdir build && cd build
/foo/glpk-4.34/configure --prefix=/bar
make && make check && make install

The upstream modifications are to Makefile.am files but the patch also
includes the implied modifications to the Makefile.in files.

Regards

Benoit