add some persistent collection classes as well as new mop elements
MOP2: fix method selection in case of null and interfaces, as has been done on master
MOP2: wire MetaClassHandle
MOP2: first try of an HAMT plus some extensions to the existing collections
MOP2: further refinement of the persistent collection api
MOP2: change HAMT to be able to directly iterate over the values instead of the entries
MOP2: update mop interfaces
MOP2: moving classes obsolete in Groovy3 to a different source folder
MOP2:moving old meta class logic plus old callsite caching helper classes
MOP2: moving some internal helper datastructures classes
add a GroovyInvoker as interface for calling methods for Groovy dynamically from Java code
add missing method stub
MOP2: enable a method being actually selected, plus some small bug fixes in the persitent collections
add simple method invocation test
MOP2: add a basic event system for meta class creations
MOP2: new test for GroovyInvoker as well as several fixes to method selection
MOP2: new basic Closure interface
MOP2: reformat
MOP2: move StringBufferWriter to outdated
MOP2: force new indy based interface usage