Gittip.trim: strip Unicode and non-printing characters

Resolves #1968
TODO: make tests operational
get Travis running JS tests
build local.env on Travis
explicitly define an install step for Travis

the added benefit here, is Travis won't try installing our
dependencies, only for us to reinstall them inside of our virtualenv
JS testing: error out if the Gittip server fails to start
make test runner and Gittip server (JS tests) use the same DB
move setup into its own file, and only run once
implement the unit tests for Gittip.trim

I'm not sure how to get the integration tests working :<
Merge pull request #1973 from gittip/1968-strip-non-printing-characters

Gittip.trim: strip Unicode and non-printing characters