remove unused Gemfile.extra file
Update Spotlight to use Blacklight 5.4 and the new if/unless feature for toggling fields on and off
refactor search results sir-trevor widget to use a custom view type widget
update to openseadragon 0.0.5
Merge pull request #622 from sul-dlss/blacklight54

Blacklight 5.4 compatibility
Initial version of slideshow block redesign
Enhanced captions display, add size option