Added Unicode support, major security improvements

Adds Unicode support so languages other than English may be encoded.

Now, instead of 3 ASCII characters encoding to 1 RGB value, 1 character
is encoded to 5 color values.  Although the information density is
lesser, it allows greater flexibility in encoding larger code points.

Adds Addition Value Position Scrambling, a new feature specific to the
Unicode version to scramble the 5 color values in a way that makes
recombining them into the original value difficult.  Different values
may be applied throughout the document.

Adds RGB scrambling so RGB values may be offset differently throughout
the document.

This commit Resolves Enhancements #1, 2, and 4.