More work for porting Config to XS

xs/xsp/Config.xsp

@@ -0,0 +1,15 @@
+%module{Slic3r::XS};
+
+%{
+#include <myinit.h>
+#include "Config.hpp"
+%}
+
+%name{Slic3r::Config} class DynamicConfig {
+    DynamicConfig();
+    ~DynamicConfig();
+    SV* get(t_config_option_key opt_key);
+%{
+
+%}
+};

xs/xsp/my.map

@@ -1,5 +1,7 @@
 std::vector<Points::size_type>  T_STD_VECTOR_INT
+t_config_option_key T_STD_STRING
 
+DynamicConfig*  O_OBJECT
 ZTable*         O_OBJECT
 TriangleMesh*         O_OBJECT
 Point*         O_OBJECT

xs/xsp/typemap.xspt

@@ -1,11 +1,13 @@
 %typemap{bool}{simple};
 %typemap{std::string};
+%typemap{t_config_option_key};
 %typemap{std::vector<unsigned int>*};
 %typemap{std::vector<double>};
 %typemap{std::vector<double>*};
 %typemap{SV*};
 %typemap{AV*};
 %typemap{Point*};
+%typemap{DynamicConfig*};
 %typemap{ExPolygon*};
 %typemap{ExPolygonCollection*};
 %typemap{Line*};