support for onTransactionConfidenceChanged in new BitcoinJKit

Signed-off-by: Jonas Schnelli <jonas.schnelli@include7.ch>
new icon from Kevin Eichhorn

Signed-off-by: Jonas Schnelli <jonas.schnelli@include7.ch>
send coins now support "enter for continue"

Signed-off-by: Jonas Schnelli <jonas.schnelli@include7.ch>
better display of last block creation time

Signed-off-by: Jonas Schnelli <jonas.schnelli@include7.ch>