Created Editable 'base' class which doesn't require models.

So, as you can see I finally created the "Editable" class. I haven't really tested the "EditableField" much but I just synced them both up. EditableField should only contain model specific code, rest should be inherited from "Editable". The idea is to have the "Editable" class for when you don't want to use models. I'm using "Editable" myself, and that works nicely.