Make ~ an operator in Vim.
Merge branch 'master' of github.com:mavam/dotfiles
Undo tildeop in Vim.

After having used it for a while, I noticed that it's really hard to appreciate
the operator semantics of ~. It turns out that the default works much better:
one often does not need to change the case of more than a single character.
Allow moving in empty space in block mode.