auto-removal of trailing spaces
Added basic keyboard shortcuts

SPACE: play/stop (or restart with SHIFT)
LEFT/RIGHT: scroll score
Fixed a small glitch with scrolling

When scrolling back to the beginning of the score with the scrollLeft
button, key display is correct.
Merge pull request #2 from boblemarin/gh-pages

1. auto-removal of trailing spaces
2. Added basic keyboard shortcuts
3. Fixed a small glitch with scrolling