Fixes issue with 12:00 PM being skipped

When using military time you can select noon, but with the AM/PM
indicator turned on you cannot ever select 12:00 PM - it get skipped.

I refactored the code that did the comparisons for >= 12:01 to a
private method so that functionality can be shared throughout the
library.
Merge pull request #22 from macfanatic/mb-fix-noon-meridan-indicator

Fixes issue with 12:00 PM being skipped