set default fee to 0.5mBTC/kb
cache xpub values in account in order to generate addresses faster
make wordlist use default language if available
get_tx_fee
fix argument for check_seed
update peers and txradar scripts
update script
signal to set fee field after payment request
Merge remote-tracking branch 'upstream/master'

Conflicts:
	lib/bitcoin.py
	lib/wallet.py
	scripts/peers
	scripts/txradar