clear up some struct/class inconsistencies MSVC complains about

src/config_cache.hpp

@@ -227,7 +227,7 @@ namespace game_config {
 		static config_cache_transaction& instance()
 		{ assert(active_); return *active_; }
 		friend class config_cache;
-		friend class add_define_from_file;
+		friend struct add_define_from_file;
 		friend class fake_transaction;
 		const filenames& get_define_files() const;
 		void add_define_file(const std::string&);

src/editor2/editor_controller.hpp

@@ -38,22 +38,22 @@ class config;
 class map_generator;
 
 namespace tooltips {
-class manager;
+struct manager;
 }
 
 namespace font {
-class floating_label_context;
+struct floating_label_context;
 }
 
 namespace rand_rng {
 class rng;
-class set_random_generator;
+struct set_random_generator;
 }
 
 namespace editor2 {
 
 class brush_bar;
-class size_specs;
+struct size_specs;
 class terrain_palette;
 class editor_map;
 

src/gui/widgets/canvas.hpp

@@ -28,7 +28,7 @@
 #include <vector>
 
 class config;
-class surface;
+struct surface;
 class variant;
 
 namespace gui2 {

src/gui/widgets/helper.hpp

@@ -19,7 +19,7 @@
 
 #include <string>
 
-class surface;
+struct surface;
 class t_string;
 
 namespace game_logic {

src/gui/widgets/menubar.hpp

@@ -30,7 +30,7 @@ class tselectable_;
  */
 class tmenubar : public tcontainer_
 {
-	friend class tbuilder_menubar;
+	friend struct tbuilder_menubar;
 public:
 	/** The direction is which the items are next to eachother. */
 	enum tdirection { HORIZONTAL, VERTICAL };

src/gui/widgets/scroll_label.hpp

@@ -39,7 +39,7 @@ class tscroll_label : public tvertical_scrollbar_container_
 class tscroll_label : public tscrollbar_container
 #endif
 {
-	friend class tbuilder_scroll_label;
+	friend struct tbuilder_scroll_label;
 public:
 	
 	tscroll_label();

src/gui/widgets/scrollbar_container.hpp

@@ -41,7 +41,7 @@ class tscrollbar_container
 {
 	friend class tdebug_layout_graph;
 
-	friend class tbuilder_scroll_label;
+	friend struct tbuilder_scroll_label;
 
 public:
 	

src/gui/widgets/vertical_scrollbar_container.hpp

@@ -27,8 +27,8 @@ class tvertical_scrollbar_container_ : public tcontainer_
 	friend class tdebug_layout_graph;
 
 	// Builders need to be able to finalize the object.
-	friend class tbuilder_listbox;
-	friend class tbuilder_scroll_label;
+	friend struct tbuilder_listbox;
+	friend struct tbuilder_scroll_label;
 
 	// Callbacks can call update routines. Note these are not further declared
 	// here only need external linkage to be friends.

src/text.hpp

@@ -23,10 +23,10 @@
 
 #include <string>
 
-class language_def;
+struct language_def;
 
 namespace gui2 {
-	class tpoint;
+	struct tpoint;
 } // namespace gui2;
 
 namespace font {

src/viewpoint.hpp

@@ -17,7 +17,7 @@
 #ifndef VIEWPOINT_H_INCLUDED
 #define VIEWPOINT_H_INCLUDED
 
-class map_location;
+struct map_location;
 
 class viewpoint
 {