Make sure we can init a minimally compiled Emacs

Symbols which would be defined only if a `window-mode' supporting Emacs
were being referenced.  Move them under a conditional.
text-mode and blank *scratch* buffer

*scratch* buffer should start in `text-mode' with no content.
Emacs 24.3: goodbye ns-toggle-fullscreen and a bug

Full screen mode on Mac OS X is now implemented in the native way
introduced in Lion.  It's not necessarily better than
'ns-toggle-fullscreen but that patch is gone.  It's time to get used to
more OS X native way of full screen support.

24.3 seems to fix the drawing but that would add an empty column to
where right fringe was.  Remove our workaround for that.

Update the README, changing the Emacs version to 24.3 and OS X to
10.8.3.
Separate 'server-start' from 'edit-server'

We might we running both on when Emacs is running under a windowing
system but break out 'server-start' hook registration from 'edit-server'
use-package macro.