Flip the position of name1 and name2 (as well as all underlying data) in an AFPChain.
This is a utility function for AFPChainXMLParser.
You will have to call AFPCHainXMLParser.rebuildAFPChain in order to get twisted groups...
Parameters:
o - ... the original AFPCHain that should be flipped
Returns:
a cloned AFPCHain which the positions of name1 and name2 flipped.