Task #57 My Charts: Calendar

- BPCalendarLayout: flow layout with fixed headers
- BPMyChartsCalendarViewController: use calendar layout
Task #62 My Charts: Cycles logic

- BPDatesManager: set cycle for date
- BPCycle+Additions: find or create cycle with index
- BPMyTemperatureControlsViewController: start new cycle when
menstruation after 20 day