No real changes, just rename "proxy_header" to "cheader"

Continue getting rid of "proxy" terminology, there is no proxy when using C
module, so it's confusing to use this term.

Lib/c/c.swg

@@ -6,7 +6,7 @@
  * ----------------------------------------------------------------------------- */ 
 
 %insert("runtime") "clabels.swg"
-%insert("proxy_header") "cproxy.swg"
+%insert("cheader") "cheader.swg"
 
 %insert("runtime") %{
 #include <stdlib.h>
@@ -19,7 +19,7 @@
 #define SWIG_contract_assert(expr, msg) if(!(expr)) { printf("%s\n", msg); SWIG_exit(0); } else
 %}
 
-%fragment("stdbool_inc", "proxy_header") {#include <stdbool.h>}
+%fragment("stdbool_inc", "cheader") {#include <stdbool.h>}
 
 %define same_macro_all_primitive_types_but_void(macro_name, TM)
 macro_name(TM, short);
@@ -354,7 +354,7 @@ template <class T> SWIGINTERN SwigObj* SWIG_create_object(T* obj, const char* sy
 }
 %}
 
-%insert("proxy_header") %{
+%insert("cheader") %{
     typedef struct SwigObjStruct SwigObj;
 %}
 

Lib/c/cexcept.swg

@@ -164,7 +164,7 @@ SWIGINTERN void SWIG_terminate() {
     SWIG_rt_throw((SwigObj *) klass, msg);
 %}
 
-%insert("proxy_header") %{
+%insert("cheader") %{
 // special value indicating any type of exception like 'catch(...)'
 #define SWIG_AnyException "SWIG_AnyException"
 

Lib/c/cheader.swg

@@ -1,7 +1,5 @@
 /* -----------------------------------------------------------------------------
- * cproxy.swg
- *
- * Definitions of C specific preprocessor symbols for proxies.
+ * cheader.swg
  * ----------------------------------------------------------------------------- */
 
 #ifndef SWIGIMPORT

Source/Modules/c.cxx

@@ -408,7 +408,7 @@ public:
     Swig_register_filebyname("wrapper", f_wrappers);
     Swig_register_filebyname("runtime", f_runtime);
     Swig_register_filebyname("init", f_init);
-    Swig_register_filebyname("proxy_header", f_wrappers_h);
+    Swig_register_filebyname("cheader", f_wrappers_h);
 
     {
       String* const include_guard_name = NewStringf("SWIG_%s_WRAP_H_", Char(module));