Merge pull request #25 from eli-b/slicing

Implemented slicing for Pattern and Track objects (issue #21)
Merge pull request #24 from eli-b/trackname_field

Added the textual trackname field to the TrackNameEvent
Merge pull request #23 from eli-b/misc-cleanup

Removed unnecessary imports, obsolete or duplicated "docstrings" and upd...
Merge remote-tracking branch 'vishnubob/master'