Use Dagger instead of Guice for Dependency Injection

[yissachar]

Dagger uses compile-time code generation instead of runtime reflection for better performance.

On the test site this resulted in instances starting up 3.5 seconds faster (a 16% improvement). On the production site this would be around 2.5 seconds, bringing the time down to 13 seconds.

The current Dagger version is a bit messy to use (at least in conjunction with Jersey/Servlets). The 2.0 version should clean things up, as well as bring even more performance benefits since it will completely remove any runtime reflection in favor of total up-front code generation and wiring.