- allow 'spend max' when opening a channel (fixes#5698)
- display amount minus fee when 'max' buttons are pressed
- estimate fee of channel funding using a template with dummy address
- Output selection belongs in the Send tab.
- Tx finalization is performed in a confirmation dialog
(ConfirmTxDialog or PreviewTxDialog)
- the fee slider is shown in the confirmation dialog
- coin control works by selecting items in the coins tab
- user can save invoices and pay them later
- ConfirmTxDialog is used when opening channels and sweeping keys
