more legible output for scripts/peers
increase timeout
Add new exchange rate options

BitcoinAverage added as new exchange rate option.

Add BitPay as new exchange rate API

Winkdex added as option for exchange rate - USD only

Cleanup exchange rate plugin

cavirtex exchange rate added

BTCChina - exchange rate
non blocking exchange rate API calls

clear combo box while waiting
change estimated_fee to include 34 bytes per output instead of hard-coded 80 (issue #520)
follow-up to #604
follow up to #604 - gtk gui