Add a database to the Wallet
This is the first in a series of PRs that will be merged into a wallet feature branch. The feature branch is being employed to prevent breaking compatibility until all of the features have been implemented.
The high-level goals for this feature branch are:
-
Instant wallet unlocking -
Ability to create wallet from a seed directly (instead of creating, then loading) -
Preserve compatibility with old wallets (by automatically converting to new format on first load)