Bring up to date with newest ozone version

Mainly the change to using objects for UDFs, which was necessary for
the scala frontend
Port global schema generator and printer to now way of doing things
First working version with sources, sinks, and map
Make schema optimisation/compaction work again
Fix KeySelector stuff and make reduce operator work
Remove KeySelector, fix stuff, add reduce fluent interface
Add combinable reduce
Add easier instantiation of the macro slave (helper)
Add flatMap, Word Count finally works now
Change how data sinks are declared
(Re)add cross operator
Move stuff around a bit
(Re)add working join operator
Fix some TODOs in data source and data sink
(Re)add cogroup and also fix some minor issues
(Re)add Union and Copy operator and also restructure
More restructuring of the codebase
Operators except iterations work now

Iterations should work but the GlobalSchemaOptimizer seems to not
support them: EdgeDependency and AmbientFieldDetection cannot deal with
the iteration operators
Finally restructure rename pact4s package to scala
Rename DataStreamNG to Scala Contract and *Macros to *Operator