Make god-mode work in special-mode buffers such as the Org agenda

god-mode doesn't work well in special-mode buffers such as the Org agenda.  These buffers bind functions other than `self-insert-command` to letter and number keys, and god-local-mode intercepts key presses by remapping `self-insert-command` to its own function.  So it fails to get a grip in special-mode buffers.

This is okay when one isn't using Evil, because in such modes bindings aren't generally prefixed with C- and M-, so there's little reason to use god-mode.

However, it's useful, at least in my own case, to use evil-god-state from the Emacs state in Org agenda buffers.  So manually remap all the single character keys to `god-mode-self-insert-command`.