pep8 fixes
use as-syntax in except clauses #38
WIP new 'make travis'

- install cython from ppa
- add python 3.3
- do not install web.py on 3.3
- run linters first to abort broken builds early

new make commands:
 - make whitespace
 - make pep8
 - make lint    # runs both of the above
 - make travis  # run on travis