refactoring of setup.py to add distutils, better import check, PEP-8++.
refactoring of setup.py to add distutils, better import check, PEP-8++.

This wholesale editing of setup.py adds:

 - PEP-8 compliant spacing, commenting, etc.

 - attempt to use setuptools (easy_install) rather than distutils.  setuptools
   is backwards compatible with distutils but supports a bunch of new options,
   including egg generation.

 - switch to imp.find_module to directly attempt import of pyx extension
   modules, rather than path mangling + 'exec import', which is more fragile
   and error prone.

 - direct use of os.path.sep instead of guessing based on os.path.join output

ctb/pygr,GenDataPro/pygr,ctb/pygr,ctb/pygr,GenDataPro/pygr,GenDataPro/pygr,ctb/pygr,theoryno3/pygr,RitwikGupta/pygr,RitwikGupta/pygr,cjlee112/pygr,theoryno3/pygr,RitwikGupta/pygr,cjlee112/pygr,ctb/pygr,theoryno3/pygr,cjlee112/pygr,cjlee112/pygr