When setting fractionDigits, use fraction_digits instead of total_digits.
Can not use an integer as the value of elt.set, use a string instead.
Merge pull request #227 from specialunderwear/master

Fix handling of Decimal.Attributes.fraction_digits
Merge remote-tracking branch 'arskom/master'
move parts of the rollover code to protocol.
remove classmethod calls.
remove dead code.
cosmetic
version bump
changelog update