CRM-18424 better amount label for repeat transactions

CRM-18424 better amount label for repeat transactions

Note that this patch also does some minor consolidation, bringing actions that relate to the is_recur checkbox into the same function.

I made the total_amount label always present, but sometimes hidden. this saves us having to check for it and also gives is a place to store data
consistently. We have been moving towards greater DOM consistency on payment pages