pieces can now be rotated in both directions.
Merge pull request #18 from asalga/bug12

pieces can now be rotated in both directions.
Fixed audio in Firefox by using simpler audio api.
Merge pull request #19 from asalga/bug8

Fixed audio in Firefox by using simpler audio api.
updated instructions with e and r keys
started game in paused state so user sees key mappings.
Merge branch 'master' into gh-pages
updated version