mh sw fixes

Warning: Use of uninitialized value in unpack at /usr/local/misterhouse/misterhouse-2.103/lib/site/ControlX10/CM11.pm line 125.
Condition: CM11 power fail detected.

Warning: Use of uninitialized value in numeric eq (==) at /usr/local/misterhouse/misterhouse-2.103/lib/site/ControlX10/CM11.pm line 182.
Condition: data received but no extended commands

Warning: Use of uninitialized value in concatenation (.) or string at /usr/local/misterhouse/misterhouse-2.103/lib/site/ControlX10/CM11.pm line 410.
Condition: DEBUG==1 and no waiting receive data (i.e. $BACKLOG)