Pre-validate paths for unregistered namespaces

- Add FedoraInvalidNamespaceException type
- Add FedoraInvalidNamespaceExceptionMapper
- Add new validatePath method to AbstractService
- Fix Unit Test that require a mock NamespaceRegistry

Resolves: https://www.pivotaltracker.com/story/show/61500426
Cleaning up Java compiler warnings
Merge pull request #482 from ajs6f/TooManyExceptions

Cleaning up Java compiler warnings
Extract a FedoraBinary interface/impl out of FedoraDatastream
Simplify DatastreamService and ObjectService contracts
Remove NodeService#findOrCreateObject
Remove unused methods from NodeService
Remove unused methods from RepositoryService
Move deleteObject() from NodeService to an instance method of FedoraResource
Pull FedoraNodes @Context parameters from methods to the class
Pull FedoraContent @Context parameters to the class level
Merge pull request #481 from fcrepo4/new-interfaces

Update core interfaces
Extract getIdentifierTranslator method
Update to Jersey 2

Resolves: https://www.pivotaltracker.com/story/show/52200823
Remove PowerMock
Cleaning up dependencies
Remove FedoraContent#create (POST .../fcr:content); functionality it duplicated by FedoraNodes#create (POST .../some/path)
Remove fcr:batch DELETE; use POST with delete requests instead
Merge pull request #490 from fcrepo4/kill-noncontroversial-methods

Kill noncontroversial methods
Added unit test to BaseHtmlProviderTest