OFconfig support for xDPd

There is an initial implementation for OFConfig 1.1.1 for xDPd. Please refer to for more details:

https://github.com/bisdn/of-config

xDPd XMP plugin required

Please refer to the manual in the ofconfig repository. Remember to compile with xmp support:

sh# ../configure --with-plugins="xmp" 
sh# make  
sh# make install