Added options:
 - disabledDates
   a list of dates that are be selectable by the user
 - disabledDatesClass
   class added to dates marked by disabledDates option (class will be
   appened to classes 'off' and 'disabled')
changed readme
Added example for disables dates
Added explanation of options to example
Finished daterangepicker disabled dates functionality
Removed console.log statements and other unnecessary code