Problem:    set_last_cursor() may encounter w_buffer being NULL.  (Matt
            Mkaniaris)
Solution:   Check for NULL.

Problem:    When setting the Visual area manually and 'selection' is
            exclusive, a yank includes one character too much. (Ingo Karkat)
Solution:   Default the Visual operation to "v". (Christian Brabandt)

Problem:    The " mark is not adjusted when inserting lines. (Roland Eggner)
Solution:   Adjust the line number. (Christian Brabandt)

Problem:    ml_get error when searching, caused by curwin not matching curbuf.
Solution:   Avoid changing curbuf. (Lech Lorens)

Problem:    The '< and '> marks cannot be set directly.
Solution:   Allow setting '< and '>. (Christian Brabandt)

Problem:    Another compiler warning for signed pointer.
Solution:   Use unsigned int argument for sscanf().