Bugfix: Return statements can implicitly cast values: a = foo(); - foo returns Object[], but a is of type Object
1) refactored infoflow problems to contain SourceManager and logger in abstract problem
2) no longer propagating into sources and sinks in the backwards solver
made the check for tainting base locals using the taint wrapper more precise to avoid unnecessary computations
1) some performance improvements
2) improved TaintWrapper.isExclusive
3) added new data for the taint wrapper