Add UA bar to top of search results page

This will both comply with [Rebdar requirements](http://redbar.arizona.edu/web-standards/banners) and provide some continuity with the Main Library site.

I chose the smaller 25px bar without the "A", since the UA/Summon logo we created is the "sidecar" style and also includes the "A".

I also discovered that for the logo (and chat) images, we can upload sizes larger than their recommendation, which is an easy way to have sharp images on HiDPI/retina screens.