moving utils inside pycparser, adding fake_stdlib argument to preprocess...

..._file and parse_file

I noticed that "utils" was being installed into site-packages (not inside pycparser). I moved utils, modified the manifest and setup.py to reflect the move. I think this is a safer location to install the utils as it avoids conflicts with other packages that might try to install their own utils directory.

Also, I added an optional keyword argument shortcut to preprocess_file and parse_file to use the faked stdlib (fake_stdlib).