save and restore last cursor position in vim

[knutwalker]

This sets vim to save the cursor position on close/write and restores it on re-opening.

• The set viminfo part is to unify and explicitly declare the .viminfo file (~/.viminfo is the default though)

• The augroup cursor part restores the cursor

  The additional check is to ensure, that the restoring works properly on files with only one line

[mathiasbynens]

Thanks!

If I pull this in, I’ll probably use ~/.vim/info instead of ~/.viminfo (cfr. ~/.vim/swaps etc.). Not sure if I really need this feature though… Let me think about it.