Add <string> fragment

Removes <string> include specifically for clang
Cuts down on duplicate #include <string> in general

Lib/perl5/std_common.i

@@ -8,9 +8,8 @@
 
 %apply size_t { std::size_t };
 
+%fragment("<string>");
 %{
-#include <string>
-
 double SwigSvToNumber(SV* sv) {
     return SvIOK(sv) ? double(SvIVX(sv)) : SvNVX(sv);
 }

Lib/python/pystdcommon.swg

@@ -195,9 +195,8 @@ namespace swig {
 //
 
 #ifdef SWIG_PYTHON_BACKWARD_COMP
+%fragment("<string>");
 %{
-#include <string>
-                                                                              
 PyObject* SwigInt_FromBool(bool b) {
     return PyInt_FromLong(b ? 1L : 0L);
 }

Lib/std/std_basic_string.i

@@ -3,10 +3,7 @@
 %include <std_alloc.i>
 %include <std_char_traits.i>
 
-
-%{
-#include <string>
-%}
+%fragment("<string>");
 
 namespace std
 {

Lib/std/std_common.i

@@ -23,8 +23,8 @@
 // Common code for supporting the C++ std namespace
 //
 
+%fragment("<string>");
 %{
-#include <string>
 #include <stdexcept>
 #include <stddef.h>
 %}
@@ -73,13 +73,7 @@ namespace std {
 #endif
 %}
 
-%fragment("StdStringInclude","header") %{
-#ifdef __clang__
-#include <string>
-#endif
-%}
-
-%fragment("StdTraitsCommon","header",fragment="StdStringInclude") %{
+%fragment("StdTraitsCommon","header",fragment="<string>") %{
 namespace swig {  
   template <class Type>
   struct noconst_traits {

Lib/tcl/std_vector.i

@@ -28,11 +28,11 @@
 //      is returned
 // ------------------------------------------------------------------------
 
+%fragment("<string>");
 %{
 #include <vector>
 #include <algorithm>
 #include <stdexcept>
-#include <string>
 
 Tcl_Obj* SwigString_FromString(const std::string &s) {
     return Tcl_NewStringObj(s.data(), (int)s.length());

Lib/typemaps/fragments.swg

@@ -149,8 +149,12 @@
 #endif
 %}
 
-%fragment("<stddef.h>", "header")  %{
-  #include <stddef.h>
+%fragment("<stddef.h>", "header") %{
+#include <stddef.h>
+%}
+
+%fragment("<string>", "header") %{
+#include <string>
 %}
 
 %fragment("SWIG_isfinite","header",fragment="<math.h>,<float.h>") %{

Lib/typemaps/std_string.swg

@@ -8,10 +8,8 @@
 
 %include <typemaps/std_strings.swg>
 
-%{
-#include <string>
-%}
-  
+%fragment("<string>");
+
 namespace std
 {
   %naturalvar string;

Lib/typemaps/std_wstring.swg

@@ -7,8 +7,8 @@
 
 %{
 #include <cwchar>
-#include <string>
 %}
+%fragment("<string>");
 
 namespace std
 {

Lib/typemaps/traits.swg

@@ -21,18 +21,12 @@
 // Common code for supporting the STD C++ namespace
 //
 
+%fragment("<string>");
 %{
-#include <string>
 #include <stdexcept>
 %}
 
-%fragment("StdStringInclude","header") %{
-#ifdef __clang__
-#include <string>
-#endif
-%}
-
-%fragment("Traits","header",fragment="StdStringInclude") 
+%fragment("Traits","header",fragment="<string>")
 {
 namespace swig {  
   /*