Adding note on laravel facade naming not being compliant with real facades

Since every joke ends up with PHP drama, I figured that [this suggestion](https://twitter.com/taylorotwell/status/441684963365097472) was worth consideration.

I'm fine with calling them "Facades" as long as:

 - it is clear that they are not facades
 - they will likely be changed with major BC breaks (5.x?)

Hope this helps avoiding transmutation of EVERY Laravel joke into drama, I'm just sick of it.