[AD] winalleg.h minipatch

[Javier González <xaviergonz@xxxxxxxxxx>]

hi, this patch is to make (when including winalleg.h)
Window's RGB macro as WINDOWS_RGB

i found that we weren't able to put it accesible like BITMAP because
RGB for windows was a macro (a define)

well, this patch makes it accesible

thank you

Attachment: winalleg.dif
Description: video/dv