Add possibility to configure RavenDB and SM

BrickPile ships with a default bootstrapper that takes care of everything for you.
If you add your own Bootstrapper to your project, derived from DefaultBrickPileBootstrapper, BrickPile will automatically detect it and use it in place of the default one.

The new initialization model resolves #162

Documentation is available here: https://github.com/brickpile/brickpile/wiki/Bootstrap-brickpile