Make mod_include do lazy evaluation of potentially expensive to

compute variables.

Tested with httpd-test's printenv.shtml.

(Justin threw in one or two unrelated formatting nits)
Submitted by:	Brian Pane <bpane@pacbell.net>
Reviewed by:	Justin Erenkrantz


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@90872 13f79535-47bb-0310-9956-ffa450edef68