CMYK images now take less space.
   This is because before I used calloc() to allocate
   space for the JSAPMPLE array, but then I had to change
   the values in the Cyan, Magneta and Yellow colors to
   UCHAR_MAX so I could have a border! This resulted in
   the C,M and Y channels having two colors, resulting in
   an 8-bit channel that resulted in a larger file size.

   Now, if a CMYK image is asked for, makejsample() will
   initialize the array to UCHAR_MAX, thus rendering all
   channels ineffective. Then, when I put in the border,
   I only change the values in the black (K) channel and
   the other three channels only have one value in the whole
   array, so they will be a 1-bit channel.

   In the example (233*233) image I tested on, the numbers
   were like this: Grey scale:47.5KB. Old CMYK: 59, New
   CMYK: 49.

I also made some small additional explanations to the
help menu and in main(), I explained where the functions
come from for an outside reader.