Form parser improvements. Solve part of #110
Music retrieval information implementation. Solve part of #110
Improvements on Segment creation. Solve part of #110
Fix formParse function dependency. Solve part of #110.
Fix Segment class definition. Solve part of #110
Flat Segment object list. Solve part of #110
Remove 'Songbook Choro' from the sources. Solve part of #110

* This collection won't be processed in this research
Fix flatten. Solve part of #110
Filters implementation. Solve part of #110
Implementation of Composers filter class. Solve part of #110
Composers filter class improvements. Solve part of #110
Implementation of Pieces filter class. Solve part of #110
Variable names improvement. Solve part of #110
Implementation of Sources filter class. Solve part of #110
Cleanup
Remotion of old filters. Solve part of #110
Composer processing in Sources filter class. Solve part of #110