have method of filtering z-addresses without a zero balance #59

Since SDL is using Hushchat, then there are a ton more z-addresses here with 0 balance. This is to document the feature request of a method to filter all addresses without zero balance so that it is easier for the user to choose an address with funds in it.

@jahway603 agreed, we should have this feature. Should it be a checkbox directly on the balance tab, or an "Advanced Setting" ? Should it be enabled by default or no?

@duke I was envisioning it as a checkbox directly on the balance tab. That's a good question about it being enabled by default. I would say no b/c I can see a new user creating a new z-address and then wondering where it is b/c there's no balance in it so it wouldn't show if this was on by default.