Updating to Reggie 3.5

1. Thumbnail images for histology items (optional)

Ticket #795 makes it possible to display the "Stained image" column in the samples list view. By default it will display the path and links for downloading the histology image connected to stained samples (see #791). By installing the ​Thumbnails extension, the column will instead display a small thumbnail of the actual histology image. Clicking on the image will display the full image in a popup window.

Note that the thumbnails extension require that Java 8 is used on the server and that Tomcat must be version 7.0.59 or higher (​http://base.thep.lu.se/ticket/1924).