Fix mod_cgi so it works on Unix systems. We need to be VERY careful

Fix mod_cgi so it works on Unix systems.  We need to be VERY careful
about calling ap_cleanups_for_exec now.  There is really no reason to call
this from outside of APR, unless you are specifically doing a fork/exec.
If you use ap_create_process, it will call ap_cleanups_for_exec for you
in the right spot now.  Also cleaned up some of the code because it helped
with debugging.  We need better error messages in mod_cgi now.
iCVS:

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@84009 13f79535-47bb-0310-9956-ffa450edef68