3.4/develop

Fully embraced the composer way of doing things, added requirement of PHP 5.4+, and added some fancy new 5.4 stuff.
It doesn't make sense to have commented out official modules inside Kohana::modules() since they don't come bundled with Kohana anymore. The official modules also weren't placed as a required dependency because Kohana doesn't rely on them to run. I think they should be added to the composer suggestion list of kohana/core.