The various changes in fpga require a rewrite of the fpga node type.
To allow relative paths for the fpga config file, Config and SuperNode
had to be modified so they store the path of the main config file.
The syntax of the fpga node type configuration has changed - the example
config in etc has been modified accordingly.
Signed-off-by: Niklas Eiling <niklas.eiling@eonerc.rwth-aachen.de>