Make GTK UI resources more consistent

The GTK UI resources have to be different resources between major versions.

When kept in one directory with slightly different filenames they were
  difficult to distinguish and resource definition was difficult to update.

The resources for both gtk versions were stored in both builds resulting in
  unneccessary increased binary size.

The new stratagy lists the UI files once in a single gresources file and only
  includes what is required. If a UI file is added it must be provided in both
  gtk2 and 3 or a build failure will occour rather than a runtime error.

frontends/gtk/Makefile

@@ -103,6 +103,7 @@ GLIB_COMPILE_RESOURCES := glib-compile-resources
 CFLAGS += -DWITH_GRESOURCE
 
 NETSURF_GRESOURCE_XML := $(NSGTK_RESOURCES_DIR)/netsurf.gresource.xml
+UI_GRESOURCE_XML := $(NSGTK_RESOURCES_DIR)/ui.gresource.xml
 MESSAGES_GRESOURCE_XML := $(NSGTK_RESOURCES_DIR)/messages.gresource.xml
 
 # generate the netsurf gresource source files
@@ -112,6 +113,13 @@ $(OBJROOT)/netsurf_gresource.c: $(NETSURF_GRESOURCE_XML) $(shell $(GLIB_COMPILE_
 
 S_RESOURCE += $(OBJROOT)/netsurf_gresource.c
 
+# generate the ui gresource source files
+$(OBJROOT)/ui_gresource.c: $(UI_GRESOURCE_XML) $(shell $(GLIB_COMPILE_RESOURCES) --sourcedir $(NSGTK_RESOURCES_DIR)/gtk$(NETSURF_GTK_MAJOR) --generate-dependencies $(UI_GRESOURCE_XML))
+	$(VQ)echo "GRESORCE: $<"
+	$(Q)$(GLIB_COMPILE_RESOURCES) --generate-source --sourcedir $(NSGTK_RESOURCES_DIR)/gtk$(NETSURF_GTK_MAJOR) --target=$@ $<
+
+S_RESOURCE += $(OBJROOT)/ui_gresource.c
+
 # generate the messages gresource source file
 $(OBJROOT)/messages_gresource.c: $(MESSAGES_GRESOURCE_XML) $(addsuffix /Messages,$(addprefix $(MESSAGES_TARGET)/,$(MESSAGES_LANGUAGES)))
 	$(VQ)echo "GRESORCE: $<"
@@ -182,7 +190,7 @@ GTK_RESOURCES_LIST := \
 
 GTK_RESOURCES_LIST := \
 	$(addprefix $(NSGTK_RESOURCES_DIR)/, $(GTK_RESOURCES_LIST)) \
-	$(wildcard $(NSGTK_RESOURCES_DIR)/*.gtk$(NETSURF_GTK_MAJOR).ui)
+	$(wildcard $(NSGTK_RESOURCES_DIR)/gtk$(NETSURF_GTK_MAJOR)/*.ui)
 
 # translations with more than just Messages files
 GTK_TRANSLATIONS_HTML := de en fr it ja nl zh_CN

frontends/gtk/res/netsurf.gresource.xml

@@ -1,32 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <gresources>
   <gresource prefix="/org/netsurf">
-    <file>cookies.gtk2.ui</file>
-    <file>cookies.gtk3.ui</file>
-    <file>downloads.gtk2.ui</file>
-    <file>downloads.gtk3.ui</file>
-    <file>globalhistory.gtk2.ui</file>
-    <file>globalhistory.gtk3.ui</file>
-    <file>hotlist.gtk2.ui</file>
-    <file>hotlist.gtk3.ui</file>
-    <file>localhistory.gtk2.ui</file>
-    <file>localhistory.gtk3.ui</file>
-    <file>netsurf.gtk2.ui</file>
-    <file>netsurf.gtk3.ui</file>
-    <file>options.gtk2.ui</file>
-    <file>options.gtk3.ui</file>
-    <file>pageinfo.gtk2.ui</file>
-    <file>pageinfo.gtk3.ui</file>
-    <file>password.gtk2.ui</file>
-    <file>password.gtk3.ui</file>
-    <file>tabcontents.gtk2.ui</file>
-    <file>tabcontents.gtk3.ui</file>
-    <file>toolbar.gtk2.ui</file>
-    <file>toolbar.gtk3.ui</file>
-    <file>viewdata.gtk2.ui</file>
-    <file>viewdata.gtk3.ui</file>
-    <file>warning.gtk3.ui</file>
-    <file>warning.gtk2.ui</file>
     <file preprocess="to-pixdata">favicon.png</file>
     <file preprocess="to-pixdata">netsurf.xpm</file>
     <file preprocess="to-pixdata">menu_cursor.png</file>

frontends/gtk/res/ui.gresource.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<gresources>
+  <gresource prefix="/org/netsurf">
+    <file>cookies.ui</file>
+    <file>downloads.ui</file>
+    <file>globalhistory.ui</file>
+    <file>hotlist.ui</file>
+    <file>localhistory.ui</file>
+    <file>netsurf.ui</file>
+    <file>options.ui</file>
+    <file>pageinfo.ui</file>
+    <file>password.ui</file>
+    <file>tabcontents.ui</file>
+    <file>toolbar.ui</file>
+    <file>viewdata.ui</file>
+    <file>warning.ui</file>
+  </gresource>
+</gresources>

frontends/gtk/resources.c

@@ -345,11 +345,6 @@ init_pixbuf_resource(char **respath, struct nsgtk_resource_s *resource)
  */
 static nserror init_ui_resource(char **respath, struct nsgtk_resource_s *ui_res)
 {
-#if GTK_CHECK_VERSION(3,0,0)
-	int gtkv = 3;
-#else
-	int gtkv = 2;
-#endif
 	int resnamelen;
 	char *resname;
 	struct nsgtk_resource_s resource;
@@ -361,7 +356,7 @@ static nserror init_ui_resource(char **respath, struct nsgtk_resource_s *ui_res)
 	if (resname == NULL) {
 		return NSERROR_NOMEM;
 	}
-	snprintf(resname, resnamelen, "%s.gtk%d.ui", ui_res->name, gtkv);
+	snprintf(resname, resnamelen, "%s.ui", ui_res->name);
 	resource.name = resname;
 	resource.len = ui_res->len;
 	resource.path = NULL;