dejavu-fonts environment collision

After splitting the DejaVuSans.ttf file into a multiple output in the
dejavu_fonts Nixpkgs expression it is not possible to install in the
user profile due to the collision.  The attached patch makes a new
package without the collision for user environment installing.

From fae78903c6ce56eda70a1a9a6914c41d248b15e8 Mon Sep 17 00:00:00 2001
From: Karn Kallio <kkallio@skami.org>
Date: Sat, 3 Sep 2016 14:09:36 -0400
Subject: [PATCH] dejavu-fonts : Prepare an environment package without
 collision.