Rework command line client and added support for new Java API interactive mode.
 - Mixing generic and specific options is supported
 - Help is action specific
 - No -a is necessary for program arguments
 - New Java API programs with main(String[]) method as entry point work
 - The 'Main-Class' manifest entry is also considered when looking for Program entry points (easier export).
Add getArity() method to Tuple
Fix TypeExtractor to work with plain Tuple and derived Tuple
Add CsvOutputFormat for new Java API
Minor consistency cleanups in CsvOutputFormat
Add convenience method to set local environments to overwrite files by default.
Clean up LICENSE and NOTICE files
Updated NOTICE file
Initial support for Group Sorting (only key positions and Reduce operators).
Fixes in TupleComparator and BasicTypeComparator