Fix fileio.c's diagram.
vim-patch:7.4.414

Problem:    Cannot define a command only when it's used.
Solution:   Add the CmdUndefined autocommand event. (partly by Yasuhiro
            Matsumoto)

https://code.google.com/p/vim/source/detail?r=v7-4-414
vim-patch:7.4.415

Problem:    Cannot build.  Warning for shadowed variable. (John Little)
Solution:   Add missing change.  Remove declaration.

https://code.google.com/p/vim/source/detail?name=v7-4-414&r=20dbceb6f4713ccd01be45dc531abc269fbb7579
Merge pull request #1282 from splinterofchaos/cmd-undef

vim-patch:7.4.414 + vim-patch:7.4.415