Use Groovy 2.0 extension modules for extension methods

[ohr]

Instead of doing MetaClass extensions, use the Groovy 2.0 extension modules mechnism

Problems:

some MetaClass extensions carry context (e.g. a ModelClassFactory or MappingService instance). This context information must be externalized into a (global) IPFContext, which needs to be accessible from static methods of the extension class.

not sure how this works with OSGi

Extensions available in commons-map, modules-hl7, platform-camel-core, platform-camel-hl7, platform-camel-cda, platform-camel-flow, platform-camel-test

[stanojevic-boris]

Added an OSGi-Activator which looks for Extension-definitions in each started Bundle and activates those Extensions for defined Classes. Closing the issue.