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.
Releasing a brand new version of a package which is exactly the same as the previous version is silly.

We should stop thinking of Kohana as a whole and instead think of it as a stack of individual packages. The more and more Kohana packages get decoupled from each other the less likely it is that all of them will need to be changed. New Kohana users will be using kohana/kohana so they don't need to go out a decipher which package version they need as they'll all be listed for them in composer.json.

Yes kohana/core will need to be incremented to 3.4 but it can be incremented with all the others when it's time to release.