Lots of minor stuff, interfaces, command line arguments (cleaned up documentation), global rspec attributes, minor node attributes, location tags, bugfixes, etc.

Basic link lookup and interface lookup is complete. Need to finish bandwidth
calculations, link types, wireless links, and interface printing.

How simple you all seemed compared to the terrible links ahead...

This also adds the disk_image tags for rspecs.

Still remaining: widearea nodes, links, osids, single-node mode.

Basic framework is in place. Availability and printability is codified into
functions now. Node.pm modified so that lookups can be done in bulk for
efficiency. When making XML, we now create XML trees rather than printing
out XML fragments.