- persisted states are saved
- state transitions are checked
- transient states are stored in channel.peer_state
- new channel states: 'PREOPENING', 'FUNDED' and 'REDEEMED'
- upgrade storage to version 21
- create unique instances of channels_dialog and addresses_dialog
- display and refresh balances in channels_dialog
- improve formatting of tx history
- repurpose left button in receive_tab