base58: add paranoid return value checks
base58: add paranoid return value checks

Rebased-From: 88df548

langerhans/dogecoin,koharjidan/dogecoin,langerhans/dogecoin,Domer85/dogecoin,koharjidan/dogecoin,marklai9999/Taiwancoin,langerhans/dogecoin,Exceltior/dogecoin,haisee/dogecoin,Exceltior/dogecoin,Domer85/dogecoin,langerhans/dogecoin,Exceltior/dogecoin,brishtiteveja/sherlockcoin,marklai9999/Taiwancoin,coinkeeper/2015-06-22_18-37_dogecoin,jarymoth/dogecoin,koharjidan/dogecoin,coinwarp/dogecoin,jarymoth/dogecoin,coinkeeper/2015-06-22_18-37_dogecoin,koharjidan/dogecoin,langerhans/dogecoin,jarymoth/dogecoin,coinkeeper/2015-06-22_18-37_dogecoin,brishtiteveja/sherlockcoin,brishtiteveja/sherlockcoin,brishtiteveja/sherlockcoin,haisee/dogecoin,jarymoth/dogecoin,coinwarp/dogecoin,coinkeeper/2015-06-22_18-37_dogecoin,coinwarp/dogecoin,Domer85/dogecoin,langerhans/dogecoin,brishtiteveja/sherlockcoin,koharjidan/dogecoin,coinwarp/dogecoin,koharjidan/dogecoin,haisee/dogecoin,haisee/dogecoin,Exceltior/dogecoin,jarymoth/dogecoin,Exceltior/dogecoin,Domer85/dogecoin,haisee/dogecoin,coinwarp/dogecoin,marklai9999/Taiwancoin,marklai9999/Taiwancoin,coinkeeper/2015-06-22_18-37_dogecoin