improve IO selection

git-svn-id: svn://svn.code.sf.net/p/fhem/code/trunk@6407 2b470e98-0d58-463d-a4d8-8e2adae1ed80
inprove peerXref

git-svn-id: svn://svn.code.sf.net/p/fhem/code/trunk@6408 2b470e98-0d58-463d-a4d8-8e2adae1ed80