Picture control minor tweak

[Henning Wallgren]

Paul,

When selecting a bitmap picture in the Picture Control Properties (as opposed to JPG), have the %SS_BITMAP set and %SS_ICON unchecked automatically.

[TechSupport]

FireFly used to work something like that. It would select the style based on the file extension (.ico vs .bmp). That changed in v1.10. Now, I leave it up to the user to make the choice.