Merge r1602978, r1683044, r1683884, r1673368, r1701717, r1683047 from trunk:

      Core filters do not need mod_proxy.h

Small speed optimization when parsing <Limit>, <LimitExcept> and environment variables


Save a few bytes in conf pool

Remove some spaces between some return statements  and ';' + fix a strange formating in a 'for' loop

In order to save a few cycles, delay a hash table lookup which is not necessary needed

Constify + save a few bytes in conf pool
Submitted by: ylavic, jailletc36, jailletc36, jailletc36, jailletc36, jailletc36
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1703405 13f79535-47bb-0310-9956-ffa450edef68