Fix combiner for group reduce.
implemented infrastructure for string style annotations
added semanticpropertyutilities
implemented parsing of the strings in SemanticPropUtil
implemented semanticPropUtils class, added compatibility to operators
Added Support for Wildcards. The following is now possible "*" for all fields constant and "1->*" when the first field is forwarded to all output fields.
Filter UDFs always considers all fields as constants
Fix group reduce compilation test
Merged and adjusted semantic annotations
Removed combine methods from CoGroup function and some minor improvements.