Update to Jersey 2

Resolves: https://www.pivotaltracker.com/story/show/52200823
Remove PowerMock
Make FedoraNodes about the resource
Memoize resource() and translator()
extract getTriples method
fix up memo
fix up signatures
Extract LdpPreferTag
Use guava machinery
fix up imports
rearrange methods
extract more helpers
Use exceptions for exceptional conditions
clean up
clean up imports
Use jax-rs constants
pull up LDP class
remove unused pagination
Make the PreferTag add the appropriate response headers
Move describe to Ldp