Make Camus build out of the box

Hey Guys,

I took a few hours today to clean up Camus a bit. Here's what I've done:

1. Restructure project into sub-projects (i.e. distinct jarts) for API, Schema Registry, ETL, and the example.
2. Added a maven install plugin to auto-magically install Kafka and the custom patched avro-schema-registry jar. `mvn clean package` should work out of the box now.
3. Added a maven plugin to auto-generate all avro java records based off of their .avsc files (and ignore the auto-gen'd files in git).
4. Re-structured packaging. I am not sure what the impact of this is (at LI, anyway), but I re-structured the com.linkedin.* stuff into com.linkedin.camus.* and did a few folder moves.

I have no real way to test if this works, other than to build it successfully. Ken, I could use your help with that.

Cheers,
Chris