error message instead of crash when texture is too big
error message instead of crash when texture is too big

svn path=/trunk/libavg/; revision=4526

yyd01245/libavg,hoodie/libavg,yyd01245/libavg,yyd01245/libavg,hoodie/libavg,th3infinity/libavg,th3infinity/libavg,scotty007/libavg,hoodie/libavg,libavg/libavg,libavg/libavg,scotty007/libavg,th3infinity/libavg,libavg/libavg,th3infinity/libavg,hoodie/libavg,scotty007/libavg,libavg/libavg,scotty007/libavg,yyd01245/libavg