New architecture: prototype pattern

[Indigo744]

Implements #117

This one is huge!
Now, $.fn.mapael is only a lightweight function wrapper to jquery to build a new object.
$.mapael is now an prototype object that is instanciated on an element.
The constructor only init some internal variable and call init().
The main modification is that this shall be use to address the current mapael object (and not Mapael anymore!). You will see that I usually assign self as this at the top of a function in order to avoid misleading name.

For the next step, there are a lot of function that can be simplify due to being in an object. For instance, a lot of internal function make use of $container as parameter, whereas it could simply be accessible from self.$container. But this will make another PR. This one is already big :)

[neveldo]

Great refactoring, thank you ! All the modifications seems to be ok :)