No BGColor with transparent pixmap symbol

[jlacroix]

When using a pixmap symbol to fill a polygon, the background color of the layer
is not used. Normally we should not see the color under the pixmap so this
behavior makes sense. However when we use the TRANSPARENT parameter of the
symbol, I think we should see the BG color instead of the color under the
current layer. I propose to change this, so we fill the polygon if the
transparent option is setted and we have a BG color.

What do you think Steve?

[sdlime]

Seems reasonable to me. Can you make the change?

[jlacroix]

Yes I'll take care of it right now. Thanks!

[jlacroix]

I fixed msDrawShadeSymbolGD and msCircleDrawShadeSymbolGD to use the BG color
with transparent pixmap symbols.

>    if(symbol->transparent == MS_TRUE && bc > -1)
>      imageFilledCircle(img, p, r, bc);

>    if(symbol->transparent == MS_TRUE && bc > -1)
>      imageFilledPolygon(img, p, bc, ox, oy); 

Marking as FIXED
This change is only in 4.3