Changes for getting Cgg into PRD

Lets merge the code back to master. 

The notable change in the code is the ability to separate the resource-loading from the base-script implementation via the ScriptResourceLoader interface. There are two of them: A system loader for CGG/PRD provided core scripts (stuff shipped within the plugin) and a user-script loader for code provided by the user (in BI-server terms: Scripts living in the solution repository).

I also consistently added a pre-compile step to all scripts, so that they can be reused. This makes not much difference for the stateless CGG-plugin, but has a nice boosting impact for PRD's more long-running objects.

Once the pull-request is merged, I will issue another one for deleting the reporting-submodule within CGG. PRD uses the CGG core directly, and all the other glue code lives within the reporting-project. This makes the buildguys job easier.