to glyphs found in the Courier New font. When mapped to code points not present
in the monospace/courier font family, a different (proportional) font is used
which messes up the "ANSI graphics" display.
- 0x10 is now mapped to U+9658 (black right-pointing pointer) instead of U+9658
  (black right-pointing triangle)
- 0x11 is now mapped to U+9668 (black left-pointing pointer) instead of U+9664
  (black left-pointing triangle)
Incidentally, 0x1e and 0x1f were already mapped correctly.

Also fixed:
- 0x16 now maps to U+9604 (lower half black) instead of U+9644 (black rectangle)

Added some helpful comments (hex values, ASCII values).