Adds a new template, a thumbnail feature, and a helper utility
The "thumbnail" feature was added to the webgeno schema. See the thumbnail feature page for an example.
relative_link.py was added as a helper script for determining the correct value to set for the "path" attribute on relative_link elements. Simply run the script and use the dialog that comes up to find the file that you want to link to. Then copy and paste the string that comes up into the "path" attribute in your relative_link.