Major refactoring+

Upgraded Blacklight to post-4.4 branch 'issue-620' in order to get code in https://github.com/projectblacklight/blacklight/commit/c2a85b2bd634d3bbce8eed0b56cc5ab52661c30f.

Added ObjectsController
Fixed customized #link_to_document helper in BlacklightHelper
Added initial objects routes
Refactored ActiveFedora::Base decorator
Added test for ObjectsController
Added pending tests for objects show view
Removed cruft - mostly unused catalog partials

Removed commented-out authorize! lines

Changed :class_name to 'ActiveFedora::Base' for compatibility with active-fedora 6.4.4+
which effectively requires the :class_name argument to refer to an ActiveFedora model
(ActiveFedora::Base or subclass) and not a module.
See https://github.com/projecthydra/active_fedora/commit/8ac538eb4442bde23e561735e00d28ff50d55744.

Fixed path helper calls in test

Updated hydra-head to 6.4.0.rc4
Updated active-fedora to 6.6.0.rc4

Update hydra-head to 6.4.0.rc4
Update active-fedora to 6.6.0.rc4