Ref: https://github.com/joelthelion/autojump/issues/249

Closes #249.

The original implementation used str.encode() on input and str.decode() on
output. However this would cause UnicodeDecodeError since certain characters
can't be encoded / decoded in ASCII.

The new solution is to use unicode() on all input strings and output UTF-8
encoded strings. This makes the assumption that the shell can handle UTF-8
strings.

The original implementation used str.encode() on input and str.decode() on
output. However this would cause UnicodeDecodeError since certain characters
can't be encoded / decoded in ASCII.

The new solution is to use unicode() on all input strings and output UTF-8
encoded strings. This makes the assumption that the shell can handle UTF-8
strings.

Closes #242.

Closes #228.

Closes #230.

2.6 EOL'ed Oct 2013, dropping 2.6 support.