Lite refactoring. Task sköter nu timeout
More abstraction. Tasks now handle timeouts etc. Lots of code removed from factoring.go :)
pollardRhoFactoring now used directly instead of generic work function as task target
removed sorting. Got +1 on kattis for that so probably good to keep for now. Also added dprint() function for debug prints.
work_function controls which factoring function should be used.
Merge pull request #4 from Tethik/master

Task abstraction