Various improvements around dependency resolution; better logging

* Now fully supports YAML dependency graphs
* Supports components referencing other components in the same package 
  with the `/SomethingInThisPackage` or just `SomethingInThisPackage` 
  convention
* Adds additional `--verbose` logging 
* Adds support for `--show-packages` flag which will list all discovered packages and their components
* Adds support for configurations that use `only: ['PackageName/*']` wildcards to include entire packages
* Improves logging when a package is unable to be resolved in the dependency graph
* Added documentation for various flags and options
As someone who just worked through this code, a few more comments would really have been welcome. I realize these are perhaps not significantly value-add, but really, this kind of thick-business-logic code used to graph an esoteric dependency system is always unpleasant to untangle (speaking as someone who has written it thrice).

I never could figure out with the moo group hates comments so much. They make code better.