Merge pull request #11 from chanunc/master

Fixed add to create & remove dummy data in template file
APIs for deleting booking
should call APIs for manipulate data instead of calling BAO directly
calling constants for getting option group name
Removed the perm hook should use permission hook instead
clean up the code
add slots detail on AJAX page for timeline calendar
rename calculateSlotPrice function to calulatePrice and moved to into Slot BAO class
don't show record payment update status options when the booking is cancelled and the payment has already been recorded
only show error when booking is cancelled and payment has already been recored.
added box for using to enter user message for the email template
don't show edit button if the booking is cancelled.
Merge branch 'master' of https://github.com/compucorp/civibooking