Javascript assert.h - move to header section

Fixes compile problem due to throw macro skullduggery in the director_throws testcase

Lib/javascript/v8/javascriptinit.swg

@@ -1,6 +1,8 @@
-%insert(init) %{
-
+%insert(header) %{
 #include <assert.h>
+%}
+
+%insert(init) %{
 
 SWIGRUNTIME void
 SWIG_V8_SetModule(void *, swig_module_info *swig_module) {