Updated the location of the About link in the header
[cleanup] Fix SSX cache and usage settins
[misc] Migrated document to xwikidoc 1.1 syntax
[cleanup] Optimized logo
[cleanup] Deleted unused images
Added the new NIH UDP logo
Move the "Read more" link from the first content paragraph next to the login/register buttons in the header
Improved the text on the (guest) homepage
Removed extra white space at the bottom of the (guest) homepage
Better rights in virtual mode