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_ivr.h

@@ -38,12 +38,10 @@
 #ifndef SWITCH_IVR_H
 #define SWITCH_IVR_H
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #include <switch.h>
 
+BEGIN_EXTERN_C
+
 /**
  * @defgroup switch_ivr IVR Library
  * @ingroup core1
@@ -179,9 +177,7 @@ SWITCH_DECLARE(switch_status) switch_ivr_session_transfer(switch_core_session *s
 
 /** @} */
 
-#ifdef __cplusplus
-}
-#endif
+END_EXTERN_C
 
 #endif