* pipi.c: add "--blur" and "--dither" commandline options.
  * blur.c dither.c: remove these examples, pipi.c works a lot better:
     pipi src.png --blur 10 dest.png
     pipi src.png --dither dbs dest.png
    (and of course combinations are possible)

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@2694 92316355-f0b4-4df1-b90c-862c8a59935f