* display chain/network in header if not mainnet
* indicate active chain/network in startup log
* specify which chain/network "fun" items apply to and only show them for that chain
* don't display exchange rates for testnet/regtest
* use block interval of 150 for regtest halving
* regtest hacks: since getblockchaininfo.blocks=0 on a default regtest node despite the genesis block existing, hack in a couple of places in order to display the genesis block
* fix /peers page to not throw error with no connections
- in tx history, request/display all inputs to get correct gain/loss values
- cross referencing for txid history from electrum
- include genesis coinbase values for genesis coinbase output address (electrum ignores the genesis coinbase TX and +50 value, but for consistency with the rest of this tool they're included)
- banner describing the electrum trust model
- ui tweaks including showing gain/loss for each address tx history item