[FEATURE] Dynamic precision

[f-aubert]

Thanks for this great and useful little library. It is only one feat. short of suiting my needs. In most case my user deals with integer (precision 0), but in some case it might want to type a dot '.' to enter a fractional amount. In this case I would rather having the parser interpret the dot '.' and not ignore it making the amount larger by adding two digits

Given a precision of 0,
typing 1234 should give $1'234
typing 1234.56 should give $1'234.56 and not $123'456