added/modified Bucket::begin(), Bucket::end() functions
added/modified Bucket::begin(), Bucket::end() functions

ZahidDev/primesieve,fredwang00/primesieve,kimwalisch/primesieve,ZahidDev/primesieve,anatoliyrazin/primesieve,kimwalisch/primesieve,ZahidDev/primesieve,kimwalisch/primesieve,tempbottle/primesieve,fredwang00/primesieve,tempbottle/primesieve,fredwang00/primesieve,tempbottle/primesieve,anatoliyrazin/primesieve,anatoliyrazin/primesieve