Fix an issue regarding implode and already-defined eq() datatype.

Tijs told us about this during the last class. Apparently something goes wrong inside implode. The eq() constructor of our AST has a conflict with a rascal-internal one (if I recall correctly). As a workaround, our eq() is renamed to keq().
Request: Add twitter bootstrap to the web forms so they look nicer.
Mention twitter bootstrap usage
Merged bootstrap stuff.