Add missing test files.

Problem:    MzScheme interface doesn't work propely.
Solution:   Make it work better. (Sergey Khorev)

Problem:    Windows: IME composition may use a wrong font.
Solution:   Use 'guifontwide' for IME when it is set. (Taro Muraoka)

Problem:    char2nr() and nr2char() always use 'encoding'.
Solution:   Add argument to use utf-8 characters. (Yasuhiro Matsumoto)

Problem:    Matchit plugin does not handle space in #ifdef.
Solution:   Change matching pattern to allow spaces. (Mike Morearty)

Problem:    The justify macro does not always work correctly.
Solution:   Fix off-by-one error (James McCoy)

Problem:    Cannot properly test conceal mode.
Solution:   Add the screencol() and screenrow() functions.  Use them in
            test88. (Simon Ruderich)

Problem:    printf() can only align to bytes, not characters.
Solution:   Add the "S" item. (Christian Brabandt)

Problem:    Message about added spell language can be wrong.
Solution:   Give correct message. Add g:menutrans_set_lang_to to allow for
            translation. (Jiri Sedlak)

Problem:    Now that 'shiftwidth' may use the value of 'tabstop' it is not so
            easy to use in indent files.
Solution:   Add the shiftwidth() function. (so8res)

Problem:    Cannot select beyond 222 columns with the mouse in xterm.
Solution:   Add support for SGR mouse tracking. (Hayaki Saito)

Problem:    Cannot complete user names.
Solution:   Add user name completion.  (Dominique Pelle)

Problem:    Cannot operate on the text that a search pattern matches.
Solution:   Add the "gn" and "gN" commands. (Christian Brabandt)

Problem:    'clipboard' "autoselect" only applies to the * register. (Sergey
            Vakulenko)
Solution:   Make 'autoselect' work for the + register. (Christian Brabant)
            Add the "autoselectplus" option in 'clipboard' and the "P" flag in
            'guioptions'.

Problem:    Can't remove all signs for a file or buffer.
Solution:   Support "*" for the sign id. (Christian Brabandt)

Problem:    Can only move to a tab by absolute number.
Solution:   Move a number of tabs to the left or the right. (Lech Lorens)

Problem:    When joining lines comment leaders need to be removed manually.
Solution:   Add the 'j' flag to 'formatoptions'. (Lech Lorens)

Problem:    ":diffupdate" doesn't check for files changed elsewhere.
Solution:   Add the ! flag. (Christian Brabandt)

Problem:    No completion for :history command.
Solution:   Add the completion and update the docs. Also fix ":behave"
            completion. (Dominique Pelle)