xmodmap keybinding for god-mode

[Steven Arntson <steven@stevenarntson.com>]

This question is more about xmodmap than god-mode, but ...

I'm starting to use god-mode and really enjoying it. There are some
directions on the maintainer's website about remapping esc to caps_lock,
for easier toggling of the mode, by writing a .xmodmap file, viz:

| remove Lock = Caps_Lock
| keysym Caps_Lock = Escape

I saved that to my ~/ and then from eshell I ran:

| xmodmap .xmodmap

And everything worked as it should. However, it doesn't keep working
that way. The rebinding turns itself off if the computer goes to sleep
for awhile, or if I restart. Is there a way to make that rebinding
permanent?  I'm running Ubuntu 14.04 and Emacs 24.4.1.

Thank you!
Steven