FORGE-890 Implementation of the new Scaffold-X plugin and API.

Contains a collection of new APIs for implementing Scaffold-X providers (that support scaffolding from X resource). This includes a Freemarker API that can be used by providers, to load templates and provide generated code. This also includes a Metawidget based API for inspecting Forge JavaClasses and obtaining inspection results.

Contains a delegating scaffold provider for Faces, so that the existing Faces provider of Forge is reused. Tests for this provider are distinct from the tests in the existing provider.
Merge pull request #320 from VineetReynolds/scaffold-plugin

The Scaffold-X API and plugins