Add gallery page to show "Who's Using VWF". Refs #2910.
Update logo backgrounds.
Update VWF users page to reflect alphabetical order.
Update catalog page demos. Fixes #2910.
Remove extra catalog image.
Update Rakefile to build catalog.htm instead of catalog.html.erb.
Update J7 description per request. Received permission to use J7 name and logo.
Remove extraneous demos from catalog page.
Merge galley and catalog back to a single page.
Reorganize demos.
Update link to cesium image to point to app folder.
Move styling to vwf.css file.
Add current session list update script back to catalog.
Switch to use javascript calls to build the catalog content.
Comment out organizations who have not yet given logo permissions.
Update descriptions on catalog page.
Only show 'Current Sessions' if any exist.
Merge branch 'development' into branch/catalog-update
Remove current sessions line when building demo entry content.
Fix AGI typo.
Fix AGI typo.