Bump JRuby to 1.7.8 and switch from Warbler/Resin to TorqBox

This bumps JRuby from 1.7.4 to 1.7.8 and updates the server used from
Warbler and Resin to TorqBox. TorqBox is based on JBoss Undertow and
is the next-generation, lightweight, embeddable version of
TorqueBox (http://torquebox.org).