Fix ukulele instrument data

- Show " (tablature)" for the ukulele tablature variant
- Add tuning data for the baritone ukulele

See http://musescore.org/en/node/24089#comment-92612 for more details.
Source of data: http://en.wikipedia.org/wiki/Ukulele
Merge pull request #617 from mgavioli/Fix_ukulele_instr_data

Fix ukulele instrument data