Periodic database backups are no longer started automatically in database.Open(), and the backup written by database.Close() can now be disabled.
Only vspd itself requires backups, they are not useful for test code or future upcoming tools such as vote-validator.
* Update linter to 1.49.0
* Move vspd into cmd directory.
This is standard practise in Decred golang repos. Especially useful when multiple executables are built from a single repo.
* Ignore bins in new dir.
