Client-side files needed for configuring a myplc inside emulab. Biggest

changes from before are a rewrite entirely in python, support for
swapmods, and of course dealing with PLC4.  The included patch is applied
to the planetlab source by plcsetup at runtime due to the way myplc
manages the bootmanager source (all the patch does is turn off hardware
requirements checking (so our nodes < pc2000 can be used) and
auto-confirms that install should proceed).