Fully integrate composer

This PR makes it so Kohana modules must be installed using composer instead of using git submodules. 

Modules with the composer type of "kohana-module" are forced to be installed into the standard vendor directory.
Modules should all have independent versioning, we may find that when we release 3.4 some modules haven't been changed and can stay at their current version. The versions of the modules which have changed can be incremented when it's time to release.