Reviewed by: lotsa folks...

Obtained from:  Howard Fear, Alexei Kosut

1) The patch that I submitted a couple of days ago which recieved
   one +1 and fizzled.  Fixes an ommision that caused include variables
   to not be parsed in config errmsg directives.  Potential
   incompatibilites are the same as the extensions of mod_include
   generally. [Howard Fear]

2) Patch submitted by Ben Yoshino <ben@wiliki.eng.hawaii.edu>
   to allow backslash quoting of characters that would otherwise
   be taken as value terminators.  Ex:
       <!--exec cmd="echo \"hello, world\"" -->
   Potential incompatibilities only to people who carelessly throw
   around '\'s. [Howard Fear]

3) Patch to fix the other part of the problem report submitted by
   Ben Yoshino <ben@wiliki.eng.hawaii.edu>.  I took that approach
   outlined in my email this morning and added a flag to parse_string
   to pass the variable name through on the exec cmd directive when
   the variable hasn't been defined.  It will still substitute a
   null value for all other directives.  It will also substitute a
   null value if the variable has been defined with a null value:
      <!--#if expr="$notset" -->   # substitutes null (if fails)
      <!--#exec cmd="echo '$notset'" -->   # echo '$notset'
      <!--#set var="notset" value="" -->
      <!--#exec cmd="echo '$notset'" -->   # echo ''
   I believe that this approach minimizes the potential incompatibilties
   for current ssi and xssi users. [Howard Fear]

4) Patch to fix compiler warnings reported by perrot@lal.in2p3.fr.
   Changes are cosmetic and shouldn't effect logic. [Howard Fear]

5) Remove HAVE_POSIX_REGEX cruft [Alexei Kosut, Rasmus Lerdorf


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@77232 13f79535-47bb-0310-9956-ffa450edef68