[RFE] Optionally allow requireBinding() to be mandatory

_From [mail4danny](https://code.google.com/u/104267830025841335740/) on June 10, 2010 05:25:57_

(This is an RFE, but I only seem to be able to create defect reports)

It would be nice to force requireBinding() calls to be mandatory as a form of documentation.

For example, if a binding in module A depends upon a binding in module B, it would be nice to fail with an error if module A doesn't explicitly requireBinding() - even if the binding is present and injection would otherwise succeed.

This would force the use of requireBinding() which is very useful documentation.

_Original issue: http://code.google.com/p/google-guice/issues/detail?id=491_