WinNT MPM: Exit the child if the parent process crashes or is terminated.

Submitted by: Oracle, via trawick

The original modification was made some years ago for Oracle HTTP Server
by an Oracle employee.  trawick made additional changes for style and
for trunk/2.4.x changes.


Follow up to r1526666:

Use SYNCHRONIZE instead of PROCESS_ALL_ACCESS because

a. it is sufficient
b. it avoids an issue where PROCESS_ALL_ACCESS is larger on
   newer SDKs, resulting in a run-time error when running on
   older Windows

Close the handle.

Submitted by: Ivan Zhakov <ivan visualsvn.com>

Submitted by: trawick
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1531000 13f79535-47bb-0310-9956-ffa450edef68