1. Added implementation in private instance method Calendar#weekly_calendar to generate a weekly calendar.

2. Renamed following class methods in module ClassMethods:

		start_date_of_week_number_in_month 			TO 		ideal_first_date_of_week_number

		starting_weekday_of_week_number_in_month 	TO 		first_weekday_number_and_date_of_week_number_of_month_in_year

   Accordingly updated the specs.

3. Added more examples under in following spec
		context ".week_number_of_year"
			it "returns the week-number of year in which given date lies"