Extracted and exposed scrollToDate:animated method
Calculate date range from given date
Merge pull request #20 from octobyte/feature/scroll-to-date

Feature - scroll to date.
[Update] Rename some variables in the method `scrollToDate:animated:`.
[Fix] An initial mark image.
[Update] Improve the data source of `RSDFDatePickerView`.

Replace the method `datePickerViewMarkedDates:` by two new methods
`datePickerView:shouldMarkDate:` and
`datePickerView:isCompletedAllTasksOnDate:`.
Resolve #21
[Update] README.

DataSource (optional).
Version bump (0.5.0)
Merge pull request #22 from ruslanskorb/develop

Version bump (0.5.0)