patch 7.4.1447

patch 7.4.1447
Problem:    Memory leak when using ch_read(). (Dominique Pelle)
            No log message when stopping a job and a few other situations.
            Too many "Nothing to read" messages.  Channels are not freed.
Solution:   Free the listtv.  Add more log messages. Remove "Nothing to read"
            message.  Remove the channel from the job when its refcount
            becomes zero.