Provide backward-compatibility for some src/Configuration.tmpl parameter names

to the canonical Autoconf-style shell variable names.  For instance
EXTRA_CFLAGS vs. CFLAGS.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80998 13f79535-47bb-0310-9956-ffa450edef68