Add testgeometry to draw a non uniform triangle

--use-texture: an option to load icon.bmp as a texture
handle mouse motion: rotate the triangle

test/Makefile.os2

@@ -2,7 +2,7 @@ BINPATH = .
 
 TARGETS = testatomic.exe testdisplayinfo.exe testbounds.exe testdraw2.exe &
           testdrawchessboard.exe testdropfile.exe testerror.exe testfile.exe &
-          testfilesystem.exe testgamecontroller.exe testgesture.exe &
+          testfilesystem.exe testgamecontroller.exe testgeometry.exe testgesture.exe &
           testhittesting.exe testhotplug.exe testiconv.exe testime.exe testlocale.exe &
           testintersections.exe testjoystick.exe testkeys.exe testloadso.exe &
           testlock.exe testmessage.exe testoverlay2.exe testplatform.exe &