Large PNG images can cause flashing in Picture controls

PNG pictures paint slower than bitmaps and other picture types. Because of the way that PowerBuilder implements Picture controls, assigning large PNG images to these controls can cause the controls to flash when they are painted or repainted. The larger the picture, the more pronounced the flash. This painting issue does not affect Picture controls in .NET targets or other types of controls (such as the PictureButton control) in standard PowerBuilder targets. [CR 536633]