WIP: Compiler and Selector

Initial version of a compiler.
I have a bad experience with .forEach(). They are syntacticly nice, but they have very bad performance characteristics. We had them in AngularJS and than had to remove them, we had them in AngularDart and then had to remove them, all in the name of performance. I would prefer if we just not use them at all and stick to good old for loop.