Change logic on Emacs version check.

The original version works for Emacs 24, but nothing beyond that. I ran into this because the latest Emacs head is (mistakenly?) reporting its version as `25.0.50.1`.
Merge pull request #23 from stafu/master

Added monky section and diff colour definitions.
Merge pull request #22 from jcsims/patch-1

Change logic on Emacs version check.
change ace foreground color to yellow