Thread: python - fe: Asyncs can occur while waiting for Ready.

Log Message:
-----------
Asyncs can occur while waiting for Ready.

Also, change the "invalid message" error(TypeError) to a ProtocolError and
fix the interpolation of that message.

Add some tests that may help reveal these issues.

Modified Files:
--------------
    fe/test:
        tracenull.py (r1.9 -> r1.10)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/fe/test/tracenull.py.diff?r1=1.9&r2=1.10)
    fe/src:
        tracenull.py (r1.19 -> r1.20)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/fe/src/tracenull.py.diff?r1=1.19&r2=1.20)