[Mono-list] Tests in linux

[Gonzalo Paniagua Javier]

Hi there!

Nick requested that 'make -f makefile.gnu test' work in linux.

Now it does. I added the tests under corlib directory only. To add other
assemblies tests you just need to add 'TEST_DIR=Test' (or whatever the
directory in which tests are) to the makefile.gnu of that assembly.

Also added a little script (mcs/class/corlib/Test/run_test.sh) that i
use to avoid typing to much when running single tests.

Enjoy!

-Gonzalo