Expose static PrintConfig objects to Perl and test apply()

xs/xsp/Config.xsp

@@ -17,3 +17,18 @@
 
 %}
 };
+
+%name{Slic3r::Config::Print} class PrintConfig {
+    PrintConfig();
+    ~PrintConfig();
+    SV* get(t_config_option_key opt_key);
+    void set(t_config_option_key opt_key, SV* value);
+    void set_deserialize(t_config_option_key opt_key, std::string str);
+    std::string serialize(t_config_option_key opt_key);
+    float get_abs_value(t_config_option_key opt_key);
+    void apply_dynamic(DynamicPrintConfig* other, bool ignore_nonexistent = false)
+        %code{% THIS->apply(*other, ignore_nonexistent); %};
+%{
+
+%}
+};

xs/xsp/my.map

@@ -2,6 +2,7 @@ std::vector<Points::size_type>  T_STD_VECTOR_INT
 t_config_option_key T_STD_STRING
 
 DynamicPrintConfig*  O_OBJECT
+PrintConfig*  O_OBJECT
 ZTable*         O_OBJECT
 TriangleMesh*         O_OBJECT
 Point*         O_OBJECT

xs/xsp/typemap.xspt

@@ -8,6 +8,7 @@
 %typemap{AV*};
 %typemap{Point*};
 %typemap{DynamicPrintConfig*};
+%typemap{PrintConfig*};
 %typemap{ExPolygon*};
 %typemap{ExPolygonCollection*};
 %typemap{Line*};