Fix malloc debug macros to work properly with h323.

The main problem here was that cstdlib was undefining free thereby causing the
proper debug macros to not be used. ast_h323.cxx has been changed to call
ast_free instead to avoid the issue. 

A few other issues were addressed:
- There were a few instances of functions improperly passing ast_free instead
of ast_free_ptr.
- Some clean up was done to avoid the debug macros intentionally being redefined.
(copied below from Kevin's commit, appreciate the help)
- disable astmm.h from doing anything when STANDALONE is defined, which is used
by the tools in the utils/ directory that use parts of Asterisk header files in
hackish ways; also ensure that utils/extconf.c and utils/conf2ael.c are
compiled with STANDALONE defined.

(closes issue #13593)
Reported by: pj



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@181135 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -4200,7 +4200,7 @@ static void register_peer_exten(struct sip_peer *peer, int onoff)
 		if (onoff) {
 			if (!ast_exists_extension(NULL, context, ext, 1, NULL)) {
 				ast_add_extension(context, 1, ext, 1, NULL, NULL, "Noop",
-					 ast_strdup(peer->name), ast_free, "SIP");
+					 ast_strdup(peer->name), ast_free_ptr, "SIP");
 			}
 		} else if (pbx_find_extension(NULL, NULL, &q, context, ext, 1, NULL, "", E_MATCH)) {
 			ast_context_remove_extension(context, ext, 1, NULL);