Testing with GHC 7.0 and 7.2.
In the process, I refactored the test suite a bit to be more robust and handle the --with-compiler more correctly in most cases. One note: I turned off the HPC tests with the GHC and WITH_GHC parameters don't match. In principle this should work but there is some sort of bug. I don't plan on fixing the bug. Signed-off-by: Edward Z. Yang <email@example.com>