PIR implementation of str2num-int.
Handle $int-parts which overflow Ints, too.
Crack the arbitrary decimal precision issue.
Handle gracefully the case of very small numbers specified as decimals.
Make the trailing zeros in the decimal part case work okay.
Provide a readme.
Refactor, so that we now have a str2num-parts function which takes fo…
…ur strings and returns a number.
str2num passes first Rat tests.
Logic in place, but no new code.
Start real routine with first tests for it.
Lots more tests, one bug fixed.
Add ten more tests, make them work.