piped logger fixes and 2.0.49 and Windows

[Jeff Trawick]

The piped logger fixes themselves have been approved for backport.

    * piped log programs respawning after Apache is stopped. PR 24805
      bogus "piped log program '(null)' failed" messages during
      restart. PR 21648.  Two people have tested a similar log.c patch
      and the worker.c patch and given feedback in PR 24805.
        server/log.c r1.137
        PREREQ: ap_mpm_query(mpm-state) support in MPMs
        (If an MPM is used that doesn't support the query, a complaint
        will be written to the error log when a piped log program
        terminates, and it won't get restarted.)
        +1: trawick, jerenkrantz, nd
However, there is a regression on Win32, BeOS, and OS/2 until/unless those MPMs 
implement the mpm-state-query function.

    * PREREQ for another fix (stranded piped logger processes) -
      ap_mpm_query(AP_MPMQ_MPM_STATE)
      No updates are available at present for the BeOS or OS/2 MPMs,
      but that is not a showstopper for the other changes.
        server/mpm/winnt/mpm_winnt.c r1.303, r1.306
        server/mpm/winnt/mpm_winnt.h r1.44
        server/mpm/winnt/child.c r1.21
      +1: trawick, stoddard
Meanwhile, I've had a couple of people asking me for the code privately, so I'm 
anxious to get this in 2.0.49 and be done with it.

Is it reasonable to commit the piped logger stuff without the Win32/BeOS/OS/2 
support?  I think yes, even though that will result in crashing piped loggers 
not being restarted on those platforms until the platform maintainers get a 
chance to work through the MPM changes.  But if anyone is going to consider 
such a regression a SHOWSTOPPER later for getting 2.0.49 out the door, then 
this would be a bad move.

Thoughts?