simplify use of bignum in util
simplify use of bignum in util

bitjson/bitcore,braydonf/bitcore,daxxog/clamcore,KainiIndustries/hullcore,Bushstar/talentcore,casinocoin/csc-bitcore-v0.1,TOMOAKI12345/bitcore,KainiIndustries/hullcore,GroestlCoin/groestlcore,bitpay/bitcore,casinocoin/csc-bitcore-v0.1,habibmasuro/reddcore,Kefkius/clamcore,iobond/bitcore,Bushstar/talentcore,casinocoin/csc-bitcore-v0.1,TOMOAKI12345/bitcore,eXcomm/bitcore,bankonme/bitcore,MulticoinExplorer/bitcore,eordano/bitcore,habibmasuro/reddcore,iobond/bitcore,Bushstar/bollycore,sEpuLchEr/bitcore,genecyber/bitcore,bitjson/bitcore,braydonf/bitcore,Bushstar/bollycore,UdjinM6/darkcore,adjoinant/bitcore,adjoinant/bitcore,Kefkius/clamcore,bitjson/bitcore,martindale/bitcore,eXcomm/bitcore,jcvernaleo/bitcore,iobond/bitcore,UdjinM6/darkcore,eordano/bitcore,jcvernaleo/bitcore,initaldk/bitcore,TeamPiggyCoin/PiggyCore,KainiIndustries/hullcore,martindale/bitcore,UdjinM6/darkcore,habibmasuro/reddcore,UdjinM6/darkcore,MonetaryUnit/bitcore,litecoin-project/litecore,olalonde/bitcore,habibmasuro/reddcore,sEpuLchEr/bitcore,Bushstar/talentcore,genecyber/bitcore,bitpay/bitcore,williamcotton/bitcore,initaldk/bitcore,martindale/bitcore,UdjinM6/darkcore,UdjinM6/darkcore,MulticoinExplorer/bitcore,olalonde/bitcore,janko33bd/bitcore,TeamPiggyCoin/PiggyCore,bitjson/bitcore,Kefkius/clamcore,pnagurny/bitcore,iobond/bitcore,MulticoinExplorer/bitcore,casinocoin/csc-bitcore-v0.1,phplaboratory/bitcore,bitpay/bitcore,sEpuLchEr/bitcore,Kefkius/clamcore,williamcotton/bitcore,bitpay/bitcore,pembo210/Litecore,lekkas/bitcore,martindale/bitcore,bankonme/bitcore,MulticoinExplorer/bitcore,KainiIndustries/hullcore,Bushstar/feathercore,Bushstar/talentcore,casinocoin/csc-bitcore-v0.1,pembo210/Litecore,maraoz/coinforge,Kefkius/clamcore,UdjinM6/bitcore-dash,maraoz/coinforge,Bushstar/bollycore,Bushstar/feathercore,KainiIndustries/hullcore,MonetaryUnit/bitcore,pembo210/Litecore,pembo210/Litecore,MulticoinExplorer/bitcore,sEpuLchEr/bitcore,KainiIndustries/hullcore,daxxog/clamcore,Bushstar/feathercore,iobond/bitcore,Bushstar/bollycore,litecoin-project/litecore,habibmasuro/reddcore,bilthon/bitcore,bilthon/bitcore,casinocoin/csc-bitcore-v0.1,lekkas/bitcore,Bushstar/feathercore,janko33bd/bitcore,sEpuLchEr/bitcore,phplaboratory/bitcore,pnagurny/bitcore