Ensure graceful handling of UTF-8 characters

Forcing the encoding to UTF-8 ensures that vim, when started in a non-UTF-8 environment, can gracefully handle the presence of UTF-8 characters in the file. Instead of generating errors, extended characters will be transliterated.

http://superuser.com/questions/556915/how-to-let-vim-listchar-work-under-not-utf8-environment

This further supports #27.