Make timer-start event restart countdown timer
Merge pull request #13 from alexandrosm/master

Make timer-start event restart countdown timer
Merge pull request #15 from alexandrosm/master

Set initial values of time unit variables, and a tiny cleanup
Fixed timing issue where pausing and restarting a countdown timer would lead to loss of a chunk of a second (timer stops immediately but begins at the next whole second down). As a side-effect, also fixed minor drift, so instead of timing e.g. 9004 millis for 9 seconds, now it comes closer to 9000 precusely