Phase out the use of jQuery UI

[Isaac-Hall]

Many mojoPortal admin pages use jQuery UI by default. We should reconfigure things so that they use bootstrap tabs/accordions etc by default instead. jQuery UI isn't bad but we're already using bootstrap in framework for many other things so there's no reason to load/use both. Since we want bootstrap for the user-facing site, we may as well use it for the admin side also.

Ideally we want this to be configurable by skin developers, but the default should be bootstrap which matches Framework.