* Allow running commands like `:diffthis` when opening multiple files.
* Add experimental extensions:
+ undo.vim (requires v7.3.005+)
+ rtscript.vim (find vimscripts in runtimepath)
* Include the workaround for <bs> and <c-h> for MS-Win. Resolve#62.
* Mention custom_ignore in readme and on the homepage. Resolve#63.
* Check the present of cwd in returned paths. Fix#64.
* Trigger Vim to remove cwd from display-names. Fix#65.
* Some internal changes and additions.
