Remove dead filterPathsForReading from FedoraPolicyEnforcement API
Fix checkstyle errors
Remove unused code from SessionFactory

Reference: https://www.pivotaltracker.com/story/show/65933082
Merge pull request #262 from kaisternad/fcrepo-65933082

Remove unused code from SessionFactory
Merge pull request #261 from daines/remove-filter-paths

Remove filterPathsForReading from FedoraPolicyEnforcement. This is just stripping out an old and unused part of the PEP interface. We do not need it.
Authorization refactoring
Rename FedoraPolicyEnforcementPoint interface to FedoraAuthorizationDelegate.
Instead of passing principals to PEP/authorization delegates, pass the session instance.
User and group principals added as session attributes.
ServletContainerAuthenticationProvider adds the servlet request as a session attribute (so authorization classes can access request IP address, etc).
Changed FedoraUserSecurityContext constructor to take a Principal instance rather than ServletCredentials.
Added additional documentation for PEP/authz delegate and other methods.

Resolves: https://www.pivotaltracker.com/story/show/66946122
Improve event reporting facilities for node property changes

Resolves: https://www.pivotaltracker.com/story/show/66603072
Fix PATCH not working in Transactions

See https://www.pivotaltracker.com/story/show/66262856