Tell the user and ask if they want to try again. If they
say no, raise a silent exception. Apply this more friendly
behaviour to the install wizard too (see issue #1668).
Benefits of this rewrite include:
- support of disconnecting / reconnecting a device without having
to close the wallet, even in a different USB socket
- support of multiple keepkey / trezor devices, both during wallet
creation and general use
- wallet is watching-only dynamically according to whether the
associated device is currently plugged in or not
Break out the workflow logic of the install wizard
into a base class. This means reimplementing with
full support in a new GUI is now easy; you just provide
ways to request passwords, show messages etc. The API
is fully documented in the base class.
There are a couple of minor outstanding issues, including that
the old messages shown when recovering a wallet are missing.
I will come back to that. Ledger wallet might be broken.
Other improvements:
The install wizard code is now easy to follow and understand.
Hardware wallets can now be restored without any need for their
accompanying libraries.
Various bits of trustedcoin were broken and have been fixed.
Many plugin hooks can be removed. I have only started on this.
