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

pbx/pbx_config.c

@@ -1754,7 +1754,7 @@ static void pbx_load_users(void)
 				c = altcopy;
 				ext = strsep(&c, ",");
 				while (ext) {
-					ast_add_extension2(con, 0, ext, 1, NULL, NULL, "Goto", strdup(tmp), ast_free, registrar);
+					ast_add_extension2(con, 0, ext, 1, NULL, NULL, "Goto", strdup(tmp), ast_free_ptr, registrar);
 					ext = strsep(&c, ",");
 				}
 			}