Image handle refactoring for win32

This contribution encapsulates the metadata of the image in an
innerclass ImageHandle which is used to create a hashmap of zoom level
to imageHandle object inside an image object, making it straight
forward to obtain any metadata information from an image for a zoom
level.

contributes to #62 and #127

Author: amartya4256

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/Image.java

@@ -2108,7 +2108,7 @@ private Rectangle getBoundsInPixelsFromNative(long handle) {
 		case SWT.BITMAP:
 			BITMAP bm = new BITMAP();
 			OS.GetObject(handle, BITMAP.sizeof, bm);
-			return new Rectangle(0, 0, width = bm.bmWidth, height = bm.bmHeight);
+			return new Rectangle(0, 0, bm.bmWidth, bm.bmHeight);
 		case SWT.ICON:
 			ICONINFO info = new ICONINFO();
 			OS.GetIconInfo(handle, info);
@@ -2119,7 +2119,7 @@ private Rectangle getBoundsInPixelsFromNative(long handle) {
 			if (hBitmap == info.hbmMask) bm.bmHeight /= 2;
 			if (info.hbmColor != 0) OS.DeleteObject(info.hbmColor);
 			if (info.hbmMask != 0) OS.DeleteObject(info.hbmMask);
-			return new Rectangle(0, 0, width = bm.bmWidth, height = bm.bmHeight);
+			return new Rectangle(0, 0, bm.bmWidth, bm.bmHeight);
 		default:
 			SWT.error(SWT.ERROR_INVALID_IMAGE);
 			return null;