Update commands: output str(Decimals), not floats
Update commands: output str(Decimals), not floats

The commands `listunspent` and `history` were using float.
Patched to consistently return strings of Decimal objects.
romanz/electrum,digitalbitbox/electrum,romanz/electrum,wakiyamap/electrum-mona,neocogent/electrum,digitalbitbox/electrum,kyuupichan/electrum,wakiyamap/electrum-mona,pooler/electrum-ltc,spesmilo/electrum,asfin/electrum,pooler/electrum-ltc,fyookball/electrum,digitalbitbox/electrum,kyuupichan/electrum,spesmilo/electrum,romanz/electrum,vialectrum/vialectrum,digitalbitbox/electrum,neocogent/electrum,asfin/electrum,wakiyamap/electrum-mona,pooler/electrum-ltc,cryptapus/electrum,fyookball/electrum,wakiyamap/electrum-mona,spesmilo/electrum,vialectrum/vialectrum,vialectrum/vialectrum,asfin/electrum,cryptapus/electrum,fujicoin/electrum-fjc,cryptapus/electrum,spesmilo/electrum,neocogent/electrum,kyuupichan/electrum,fyookball/electrum,fujicoin/electrum-fjc,fujicoin/electrum-fjc,pooler/electrum-ltc