[RFC] Remove modelines

Removed modelines are better than modelines that differ from file to
file.

You can easily set up Vim for this project via:

```vim
au  BufRead,BufNewFile  /data/neo/*.{c,h}  set cinoptions+=>2 sts=2 sw=2
```
or
```vim
au  BufRead,BufNewFile  /data/neo/*.{c,h}  call NvimSettings()
```
..and the like.