Add support for in-memory database

Set "Database" parameter in config to ":memory:" to enable.
Upgrade System.Data.SQLite to 1.0.94

This will allow us to use the FullUri property in our connection strings
to specify named in-memory databases.
Add support for FullUri connection string property

This fixes transactional unit tests by using a named in-memory
database instance with shared cache. Without shared cache, you can not
have more than 1 connection open at a time to an in-memory database.
Run SQLite unit tests in memory to prevent locking issues