Add error handling when Event userdata is empty/null.

Resolves: https://www.pivotaltracker.com/story/show/78467744
Simplify component scanning to the 'org.fcrepo' package

Resolves: https://www.pivotaltracker.com/story/show/78517974
Add fedora:object to federated filesystem directories

- Replace loop/flag logic with Guava one-liners

Resolves: https://www.pivotaltracker.com/story/show/70990124