* refund address handling improvement
* fix compilation error
* Remove unnecessary line
* restrict to view
* fix comment
* Improve handling of gas limits
* get test to pass - check that the return data is appropriately long before decoding
* modification to checking inequality
* modification to checking inequality - use unchecked
* clean functions around - add untrustedBaseDeliveryPrice
* make quote_length_bytes a constant
* seperate pay into two overloads
* change inequality to equality for checking return data length
* renaming functions
* allow override of refund per gas unused
* test modification
* note