Refactored ResourceMerger to improve reusability and eliminate unnecessary type parameters.

This is a breaking API change, so incremented the version as well.
Added ResourceMerger.toFunction()

...as a complement to Fluent*Resource.toFunction().
Added Guava dependency back in
Small doc fix
Added missing TextLineFileResource.equals() and hashCode() methods, and the test that found the problem
Added more TextLineFileResource tests