Reception times/dates.
Exhibition thumbnail hover UJS.
Add poster and press release upload.

Refactor uploaders.
Fix thumbnail generation to resize_to_fit.
Preload exhibition images for hover display.
Clean assets.
Add formatting for press release and poster.
Speed up homepage slideshow to 3 seconds/slide.
Prepare to dynamicize contact, history, about.

* Break up redarrow.css into stylesheets per page.
* Create controllers for about, history, contact.
* Update routes.
* Create history info table.