Large refactoring work on PollService (untested)
AndroidManifest.xml:
-changed min API version back to Ice Cream Sandwich, enhanced notifications are shown if running on a device with API version of 16 or higher

PollService.java:
-broke onHandleIntent() into many smaller functions (untested, may not work)

CalEvent.java:
-broke ringer states into a separate internal Class RINGER

MainActivity.java, ResetEventService.java, SkipEventService.java:
-updated to reflect variable changes in CalEvent and PollService