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_resample.h

@@ -42,11 +42,9 @@
 #ifndef SWITCH_RESAMPLE_H
 #define SWITCH_RESAMPLE_H
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-#include <stdlib.h>
 #include <switch.h>
+BEGIN_EXTERN_C
+#include <stdlib.h>
 
 /*!
   \defgroup resamp Audio Resample Functions
@@ -158,10 +156,7 @@ SWITCH_DECLARE(void) switch_swap_linear(int16_t *buf, int len);
 
 ///\}
 
-#ifdef __cplusplus
-}
-#endif
-
+END_EXTERN_C
 
 #endif