+ Updated information about the S-Lang colour pair shortage bug.
  * src/graphics.c:
    + Implemented the solution explained in NOTES.

+ Added a section with a proposed solution to the slang problem.

+ Default to ncurses, not slang, because slang only has 128 colour pairs.
  * src/caca.c:
    + Disable scrolling to avoid hashmap scrolling optimization code.
  * src/graphics.c:
    + Swap fg and bg in the colour pair indexing, so that bg is always
      right.
    + Disable alt charset support to exploit my patched slang.

+ Dither chroma outside of rgb2hsv_default().
    + Clip fromx and fromy values.
  * NOTES:
    + Link to the XTerm control sequences.
  * examples/view.c:
    + Draw status bar.
    + Move with 'h' 'j' 'k' 'l', à la vi.
    + '?' toggles a help menu.

+ Added setab/setaf quotes from the XTerm terminfo.
    + Proposed a workaround for bright colours on any terminal.
  * src/caca.c:
    + 16 colour support for ncurses and conio.
  * src/graphics.c:
    + Ported to 16 colour support.
    + Added a missing <stdio.h> for BUFSIZ.
    + Disabled vsnprintf under DOS (only vsprintf exists).
  * examples/:
    + Don't abort if the caca.txt sprite was not found.
    + Ported to 16 colour support.