avoid too much allocs on software start-up

- this funct will be used a lot in the widget constructors

src/ce_sharedres.pas

@@ -9,12 +9,11 @@ procedure AssignPng(ctrl: TControl; const resName: string);
 
 implementation
 
-procedure AssignPng(ctrl: TControl; const resName: string);
 var
   png: TPortableNetworkGraphic;
+
+procedure AssignPng(ctrl: TControl; const resName: string);
 begin
-  png := TPortableNetworkGraphic.Create;
-  try
   try
     png.LoadFromLazarusResource(resName);
     if ctrl is TCustomBitBtn then
@@ -23,13 +22,12 @@ begin
       TCustomSpeedButton(ctrl).Glyph.Assign(png);
   except
   end;
-  finally
-    png.Free;
-  end;
-
 end;
 
 initialization
+  png := TPortableNetworkGraphic.Create;
   {$I ../src/ce_icons.inc}
+finalization
+  png.Free;
 end.