Author: Shamim Rezaie
MDL-69166 core_payment: payment gateways can have a surcharge
http://git.moodle.org/gw?p=moodle.git;a=commit;h=e3e83185edd48be5655245d83f7f3d5f5b585864
http://github.com/moodle/moodle/commit/e3e83185edd48be5655245d83f7f3d5f5b585864
+ 4.0 en [feeincludesurcharge,payment]
+ 4.0 en [surcharge,payment]
+ 4.0 en [surcharge_desc,payment]