[lmi] Intermittent unit-test failure

[Greg Chicares]

For the first time ever, I just now saw this failure:

Running system_command_test:

**** test failed: Expression 'system_command("grep --quiet xyz eraseme")' 
failed to throw expected exception 'std::runtime_error'
[file /lmi/src/lmi/system_command_test.cpp, line 49]

**** 1 test errors detected; 1 tests succeeded

Running it in a loop:
  /lmi/src/build/lmi/CYGWIN_NT-5.1/gcc/ship[0]$while true; do 
./system_command_test.exe --accept && echo okay; done
I see it fail on the order of ten percent of the time.

It should be calling this function in 'system_command_non_wx.cpp' for msw:
  #else  // defined LMI_MSW
  void concrete_system_command(std::string const& command_line)
which calls CreateProcessA() and WaitForSingleObject(); is there a flaw
in the way those msw functions are used?