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.
Definitely worth adding the other core modules to the suggest list on kohana/core, but surely kohana/kohana should stay as a complete sample project and therefore should have the core modules in its composer.json and present but commented out in the bootstrap (just like we used to with submodules).

People shouldn't be using kohana/kohana as a dependency, they should be using it as an example of how to set up their own project root repository so it's better to have everything in and then take out what you don't want/need.

I agree that all vendor modules should be in vendor/, not modules/. The `kohana-module` composer type is useful-ish for identifying what the package is, so perhaps in the short term we should encourage people to override the custom install path (to put it back to the standard path) in their composer.json as below:

```json
"extra": {
    "installer-paths": {
        "vendor/{$vendor}/{$name}": ["type:kohana-module"]
    }
  }
```