switch from vim to neovim

This commit replaces the whole vim directory by the new directory, which
is managed by neobundle - a bundle manager in the vim/neovim area.
Neovim comes with it's own config file as well, which I included in the
new vim directory an link into the home directory.
remove trailing whitespaces
something with mutt
something with git/ignore
fish alias for gti - misstyped git
change date format in tmux status bar