Problem:    .xz files are not supported.
Solution:   Recognize .xz files so that they can be edited.

Problem:    synIDattr() cannot return the font.
Solution:   Support the "font" argument. (Christian Brabandt)

Problem:    Unicode double-width characters are not up-to date.
Solution:   Produce the double-width table like the others.

Problem:    MzScheme interface can't evaluate an expression.
Solution:   Add mzeval(). (Sergey Khorev)

Problem:    Tables for Unicode case operators are outdated.
Solution:   Add a Vim script for generating the tables.  Include tables for
            Unicode 5.2.