Prevent running doomed tests. They weren't being run
by the old testing infrastructure.
Enable as many "og" lit tests. Several fail because they weren't
being executed previously!

    Boogie :: og/DeviceCacheSimplified.bpl
    Boogie :: og/DeviceCacheWithBuffer.bpl
    Boogie :: og/async.bpl
    Boogie :: og/houd1.bpl
    Boogie :: og/lock-introduced.bpl
    Boogie :: og/termination.bpl
    Boogie :: og/treiber-stack.bpl
Made lit tests slightly less fragile under OSX/Linux by passing flags to ignore
DOS line endings and whitespace to diff tool.
Remove old python testing scripts
Remove some legacy test infrastructure for OSX/Linux
Prevent lit tests from running on OSX/Linux if mono is not in
the user's PATH
Added script for cleaning up temporary files created by both the lit
and legacy (batch file) testing infrastructures. This unfortunately
is required if switching between infrastructures because both systems
create a file named "Output". However for lit it is a directory and
for the legacy system this is a simple text file.