Show images in files inline.
Merge branch '2049-run-job-from-workbench' into 1971-show-image-thumbnails
In theory this works but I need a keep server to test it.
Tested, works great.
Made regex case-insensitive and added svg to list of extensions.
Merge remote-tracking branch 'origin/master' into 1971-show-image-thumbnails
Merge branch 'master' into 1971-show-image-thumbnails

Conflicts:
	apps/workbench/app/views/collections/_show_files.html.erb
Merge branch '2376-show-collection-tags-everywhere' into 1971-show-image-thumbnails

Conflicts:
	apps/workbench/app/controllers/actions_controller.rb
	apps/workbench/app/views/collections/_show_files.html.erb
Added thumbnail option to #link_to_if_arvados_object, enabled on pipeline instance and job pages.
Refactored #is_image and #file_path to CollectionsHelper.
Merge remote-tracking branch 'origin/master' into 1971-show-image-thumbnails
Thumbnail behavior now conforms to original story
Added documentation to a few methods
Merge branch 'master' of git.clinicalfuture.com:arvados

Conflicts:
	apps/workbench/app/helpers/application_helper.rb