virtualenv in it's own directory
ignore virtualenv directory
make bitrate optional
Added indexed tracks stats
Added elapsed time stats
Encapsulated track adding and skipping
Added counter by extension
Average time per track
Removed ext cache
Merge pull request #69 from felixhummel/indexer_works_for_me

make bitrate optional
Merge pull request #68 from felixhummel/virtualenv_in_separate_directory

virtualenv in it's own directory