Feature/edit button on results

This feature adds Edit and Destroy buttons to the search results and detailed search results. Only authorized users can see the buttons. 
After the feature is implemented I suggest we modify nyucore.rb#index, which now lists all nyucores object without pagination. 
The following files were added:
﻿app/views/catalog/_document.html.erb
app/views/catalog/_show_default.html.erb
features/edit_button_on_results.feature
feature/step_definitions/edit_button_steps.rb
The following files were modified
app/controllers/nyucore_controller.rb
feature/step_definitions/record_steps.rb


@ekate Based on the feature name I'd expect the description here to talk about both destroy and edit buttons, but as I write that I do think this should be two smaller features, one for edit and one for destroy. Just separate the stories below.

Also I think the edit portion should be part of [this feature](https://github.com/NYULibraries/ichabod/blob/development/features/edit_metadata_authorization.feature). And maybe it already is but that feature needs to be edited for this workflow.