Fix styles (#47)
Fix scrolling behavior (#49)
PERIOD is gone.  SELECTED_PERIOD has become RANGE
Lots of code cleanup, adding tests, changing SELECTED_PERIOD behavior to match Hipmunk (which has the best period-selection behavior I've seen in an Android app)
More docs on the new RANGE behavior
Merge pull request #50 from square/edenman/bugfixes

Fix #47 and #49