Merge pull request #24 from thallgren/feature/binder

Treat all Ruby Integer values as PIntegerType
Add the first cut of the Binder.

This implementation processes:
- effective categories
- bindings in layers

and produces a Hash[Key, InjectorEntry] that can be fed to an Injector.
Add first cut of Binder.

This is the first cut of the Binder which is configured from bindings
data. Once configured it is used to instantiate an Injector (t.b.d).