PTEUDO-1991 on restore failure, create a fresh schema

[drewwells]

When a database is partially or fully restored, we fail to
migrate to it. This is problematic as user can not easily
recover from this situation.

We will attempt to version the schema by migrating whatever
is there and starting with a new schema. In situations where
the issue is the pgdump itself, we will be creating multiple
copies of an empty schema which is cheap. In more typical
situations, we will move a partially or fully migrated schema
to another location and attempt a restore with a fresh schema.

- change restore to return sql errors rather than exit codes
- sanitize dsn emitted by restore

[drewwells]

Dropping the database was more pain than it was worth. I think we can get by with dropping the schema BEFORE attempting a restore. The schemas will be recreated by name as the role associated with the application.

[drewwells]

Kind of a lot of changes, let's do this after the 1.10.1 release