Locate test data from __file__

Find c_files and fake_libc_include from __file__ of the unit test,
rather than expecting the test suite to be run from a particular
directory.
Cosmetic whitespace fixes
cleanups
moar cleanups
More cleanups - whitespace, copyrights, etc.
Update Python 3 version in tox.ini to 3.3
Merge pull request #13 from stefanor/relative-tests

Locate test data from __file__
Merge branch 'master' of github.com:eliben/pycparser
Clean up whitespace in test code
Run post install task executing _build_tables

* Add post install task executing _build_tables in install destination
* Use distutils execute for building tables to respect dry_run flag
* Name the overriden class install to get the right help text
* Also run _build_tables when creating a source distribution
* No more need to run _build_tables.py manually

Closes #5