use macro for EXTERN "C" begin and end lines in header files to clean up the headers, and to eliminate a format bug in emacs.

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@1291 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/include/switch_channel.h

@@ -38,15 +38,10 @@
 #ifndef SWITCH_CHANNEL_H
 #define SWITCH_CHANNEL_H
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-#ifdef __FORMATBUG
-}
-#endif
-
 #include <switch.h>
 
+BEGIN_EXTERN_C
+
 struct switch_channel_timetable {
 	switch_time_t created;
 	switch_time_t answered;
@@ -380,8 +375,6 @@ SWITCH_DECLARE(switch_status) switch_channel_set_raw_mode (switch_channel *chann
 SWITCH_DECLARE(switch_status) switch_channel_get_raw_mode (switch_channel *channel, int *freq, int *bits, int *channels, int *ms, int *kbps);
 /** @} */
 
-#ifdef __cplusplus
-}
-#endif
+END_EXTERN_C
 
 #endif