Allow overload for every classes.

Minify_Core becomes Kohana_Minify, but the overload is the same.

Signed-off-by: Guillaume Poirier-Morency <guillaumepoiriermorency@gmail.com>
Merge branch coffeescript into '3.2/develop'

Conflicts:
	classes/minify/driver.php
	classes/minify/driver/csstidy.php
	classes/minify/driver/jshrink.php
	classes/minify/driver/lessphp.php
	config/minify.php

Signed-off-by: Guillaume Poirier-Morency <guillaumepoiriermorency@gmail.com>