avoid too much allocs on software start-up

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

src/ce_sharedres.pas

@@ -9,27 +9,25 @@ procedure AssignPng(ctrl: TControl; const resName: string);
 
 implementation
 
-procedure AssignPng(ctrl: TControl; const resName: string);
 var
-  png : TPortableNetworkGraphic;
-begin
-  png := TPortableNetworkGraphic.Create;
-  try
-    try
-      png.LoadFromLazarusResource(resName);
-      if ctrl is TCustomBitBtn then
-        TCustomBitBtn(ctrl).Glyph.Assign(png)
-      else if ctrl is TCustomSpeedButton then
-        TCustomSpeedButton(ctrl).Glyph.Assign(png);
-    except
-    end;
-  finally
-    png.Free;
-  end;
+  png: TPortableNetworkGraphic;
 
+procedure AssignPng(ctrl: TControl; const resName: string);
+begin
+  try
+    png.LoadFromLazarusResource(resName);
+    if ctrl is TCustomBitBtn then
+      TCustomBitBtn(ctrl).Glyph.Assign(png)
+    else if ctrl is TCustomSpeedButton then
+      TCustomSpeedButton(ctrl).Glyph.Assign(png);
+  except
+  end;
 end;
 
 initialization
+  png := TPortableNetworkGraphic.Create;
   {$I ../src/ce_icons.inc}
+finalization
+  png.Free;
 end.