Refactor bind bundle in Binder into an ICommand.

In an effort to massively improve the code in the Binder, the gigantic
class is being broken into ICommand based classes. This commit refactors
the bundle binding code by simply extracting the existing code from
the Binder into the BindBundleCommand and friends. Improving the code
comes after this fundamental refactoring step.
Minor code clean up after major refactoring.