OOB Hostname a link now in equipment view

It is nice to be able to click on the OOB Hostname get straight to the
equipment to be managed. This commit implements it
Indicate security updates in plain-text output

Add a fourth column to package.txt, indicating whether an update is a
security or a normal update.

Signed-off-by: Apollon Oikonomopoulos <apollon@skroutz.gr>
Inventory: add resources for Dell servers

Add Driver and Support links for all Dell servers. The interface is
generic enough to be extensible for other manufacturers/resource types.
The template renders all (<description>, <url>) tuples under
host.resources accordingly.