Revert changes for SIGASH_RANGEPROOF #215
Description
The changes made to support SIGHASH_RANGEPROOF are not tested and they look buggish after a double check.
It would be better to revert the changes introduced with 1fe2fd4#diff-65cf78187bd6604d27914dc21ac7c788475467c516e819f795a609b84bb6fe54 and eventually open a dedicated PR later with proper unit tested changes.