Optimize 'isInDisableDates' and 'isInEnableDates' to O(1) time from O(n); Add 'setDisabledDates' function
Merge pull request #206 from domis86/master

 improve slow 'isInDisableDates' and 'isInEnableDates' functions, add 'setDisabledDates' - closes #205
Merge remote-tracking branch 'upstream/master'