Add tbuisp, a frontend to uisp, the program used to upload code to
motes. Takes care of testbed permissions checking, and figuring out
most of the command-line arguments to uisp (like the programming board
chipset and microcontroller part number).

For now, only supports uploading code to a mote, and has debugging
output turned on.

Depends on 'uisp' being installed - right now, that doesn't happen
automatically. Probably what I should do is import the uisp code into
our CVS tree, since it's GPLed, and not _too_ huge ( O(dozen) files. )