Fixed several bugs that prevent some files to be opened in GP :  - String tunings for bass  - Removed chords that are not used in the track  - In chords : set -1 to strings that are not fretted instead of undefined negative number (should be uint.MaxValue - base fret)  - Voices and Bars should not be reused, it breaks some references.
Fixed several bugs that prevent some files to be opened in GP :
 - String tunings for bass
 - Removed chords that are not used in the track
 - In chords : set -1 to strings that are not fretted instead of undefined negative number (should be uint.MaxValue - base fret)
 - Voices and Bars should not be reused, it breaks some references.

fholger/RocksmithToTab