Merge pull request #17 from jpalandri/master

corrected help message with key binding
Revove wrongly added tabs from version control.
Merge branch 'remove_tabs'
Chord bass attribute
Split regexp in capturing and non capturing in notes module
Simplified Chord.parse method
Basic chord parsing tests
Test chord w/bass parsing
memoized functions return copies of objects
ChordFinder support bass
@memoize cache immutability test
Merge branch 'issue-16-bassed-chords'

Closes #16
Remove unnecessary API
Fix key normalization. Nasty missing parens bug
More tests
Merge branch 'more_coverage'
More tests
Merge branch 'more_coverage'
Key and KeyOctave have text methods
Merge branch 'issue-19-major-dont-rely-on-key-string-representation'

Fixes #19