+ Minor change to the dithering names.
  * TODO:
    + Added cacaview TODO.
  * doc/cacaview.1:
    + Wrote a manpage for cacaview.
  * examples/Makefile.am:
    + Moved the -DX_DISPLAY_MISSING=1 here.
  * examples/view.c:
    + Capital 'D' cycles through dithering modes in reverse order.
    + Sleep when there is nothing to do.
    + Cosmetic code reorganisation.