Re-implement and adapt resource delegate generators as an extension.

Summary of squashed commits:
Extract part of delegated method generation to velocity + framework.
Extracted the complete output of delegated methods to template
Added basic root pom to help IDE import
Imported client and test code for delegates.
Use parameterized name when possible
canGenerate() should not throw
Generate delegates for sub resources
Ensure delegate methods are valid before generating
Don't use die() to fake a return value
Improved method generator restrictions
Merge pull request #2 from ArcBees/cv_rest_resource_delegate_p1

Resource Delegates