Squashed 'zsh/prezto/' changes from 3f556400..7b5196ca
Squashed 'zsh/prezto/' changes from 3f556400..7b5196ca

7b5196ca ssh: check ssh-askpass presence under Linux

git-subtree-dir: zsh/prezto
git-subtree-split: 7b5196ca66a28c3555f3ab32b911d009277d49bd

skjerven/dotfiles,skjerven/dotfiles,skjerven/dotfiles