Add some tests for taddr2uaddr and reverse

Signed-off-by: Olaf Kirch <okir@suse.de>
Introduce rpctest_log_tagged

Signed-off-by: Olaf Kirch <okir@suse.de>
Using log_test_tagged with netconfig tests

Signed-off-by: Olaf Kirch <okir@suse.de>