emacs: prevent escape exiting god-mode

only use escape to enter it. use i to exit it.
Revert "emacs: nice bindings for common navigation cmds"

This reverts commit 5c34fc6617eb7792a5bbbf08d0ef2ac4b21d2bf7.

Quite a lot of modes bind "M-p" and "M-n", which interferes with using
them to cycle through grep hits.