1. Added automatic Makefile generation - just dumps out a string into a
Makefile. The string contains the gross sed hack.
2. Added some helper functions to run commands from wtihin the compiler.
Currently returns only the output of the command.
[cleanup] will need to check exit value of process as well, handle
failures
3. Moved 'generateDriver' into the code generator - currently
OptiMLCodegenC. This can then be specialized for each code generator.