Readme: segfault in AppNotes/AN1182 only happens on Linux, not with Windows

For reference, the segmentation fault happens in Primitive.c
OutCharRender() when executing this instruction:
    temp = *(pParam->pChImage)++;
SDL: support for clipping

The AppNotes/AN1182 demo now clips the Thai font so that it is not drawn
outside of the box.

Also some drawing issues in ObjectLayer demo clock setting for the
month/day/year drop down menus are gone now.