Selection handled in its own class

All selections are now stored in a GLLSelection object, which can also
do limited conversions (specifically: If you select an item, it also
marks all bones as selected). It's not all perfect yet, but this should
make it much easier to alter the selection from the render view.
Foundations for selecting by mouse

Work in progress
Shortened a lot of code by expressing things in a functional way, especially using map.

I've got a lot of cases where I got one array/dictionary/whatever, and I want to create another one using the objects from the first transformed in some way. This is exactly what map is for, and it used to be rather ugly before. There are also some cases of makeObjectsPerformSelector: and the like.
Add additional controllers.
Merge.
Fixed code that didn't compile

Now it does