Tiny cosmetic string changes for Appearance prefs.

* More general tab title "Decorators"
* Sentence casing "Window decorator:". Here the "Window" is OK,
  there could be "OSD decorators" etc. in the future.

src/preferences/appearance/APRWindow.cpp

@@ -55,7 +55,7 @@ APRWindow::APRWindow(BRect frame)
 	fColorsView = new APRView(B_TRANSLATE("Colors"));
 
 	fDecorSettings = new DecorSettingsView(
-		B_TRANSLATE("Window Decorator"));
+		B_TRANSLATE("Decorators"));
 
 	fAntialiasingSettings = new AntialiasingSettingsView(
 		B_TRANSLATE("Antialiasing"));

src/preferences/appearance/DecorSettingsView.cpp

@@ -48,7 +48,7 @@ DecorSettingsView::DecorSettingsView(const char* name)
 	// Decorator menu
 	_BuildDecorMenu();
 	fDecorMenuField = new BMenuField("decorator",
-		B_TRANSLATE("Window Decorator:"), fDecorMenu);
+		B_TRANSLATE("Window decorator:"), fDecorMenu);
 
 	fDecorInfoButton = new BButton(B_TRANSLATE("About"),
 		new BMessage(kMsgDecorInfo));