Add function to emulate the execution of #! scripts

for OS's which don't support starting them automatically
(enable with #define NEED_HASHBANG_EMUL)

Obtained from: tcsh-6.07.05, written by peter@zeus.dialix.oz.au (Peter Wemm)


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@79994 13f79535-47bb-0310-9956-ffa450edef68