Add support for escaping all non-ascii chars to ap_escape_html, and use

it to fix PR#25202: encoding="entity" doesn't work as advertised in
mod_include.
For backport, this'll need an ABI-preserving version that'll be
a minor MMN bump.  But if we do that in /trunk/, it'll never change.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@730296 13f79535-47bb-0310-9956-ffa450edef68