Add Node modules to buildout process

This adds the node modules jshint and karma to the buildout process. Users on mf1lt don't need to install anything to build and run mf-next fully. (mf1lt does contaion node, npm and phantomjs).

In addition to this, the default compilation level was raised to ADVANCED_COMPILATION. If you need to customize this, use the user specific buildout configuration.

The javascript unit tests are now run as part of the buildout process. New targets [js-tests] and [js-tests-debug] were added.

Adapted documentation to reflect these changes.

Adapted travis configuration to work with this new buildout configuration.