The files in this directory are are used by Pancho to add vendor support.  
They will be included if they end in .pm and include a device_types method.  
The 'Plugin.sample' file in this same directory provides a skeleton of a basic
plugin file.  The methods that are in it are required in order for the
plugin to work properly (i.e. these are invoked by Pancho and therefore must
exist).  Any number of devices can be handled by a plugin but it is probably
best to keep it to one vendor just for clarity.

If you write a plugin please submit it to the Pancho HQ to be included in 
future releases.
