3.4/develop

This pull request is in relation to my other pull request: https://github.com/kohana/kohana/pull/27
This pull request passes all unit tests.

---

APPPATH has been completely removed from the core!

Kohana::modules() now loads modules in order instead of bottom to top. This really confused me when I first began using Kohana and I'm sure everyone would agree this is much more intuitive (for a programmer at least).

Core and application modules are now explicitly enabled using Kohana::modules() instead of magically being added in the on initiation. This gives the user greater control, and gives them a better understanding on what's really going on instead of lying to them. One benefit is you can now run Kohana without the application module if you wanted.

Kohana::$_paths was removed and replaced with Kohana::$_modules. The only difference between the two was that $_paths had numeric keys instead of the module names therefore it didn't need to exist.

Magic quotes, safe mode and register globals support has been removed since they are removed in PHP 5.4.

Debug::path() now also uses the paths of enabled modules when shortening a path. For example: "/var/www/kohana/vendor/kohana/database/classes/Database.php" becomes "{module:database}/classes/Database.php".

All direct access checks "<?php defined('SYSPATH') OR die('No direct script access.');" found at the start of classes and generated logs have been removed.