Add launcher script

I tried to package this program in Ubuntu, and found that it has no
startup script. So I added a `colout` script that gets installed into
the scripts directory with the `setup.py`.

bin/colout

@@ -0,0 +1,11 @@
+#!/bin/bash
+# Copyright © 2013 Martin Ueding <dev@martin-ueding.de>
+
+# Small launcher script for the main module.
+
+# Licence: GPL 3+
+
+set -e
+set -u
+
+python -m colout.colout "$@"

setup.py

@@ -29,6 +29,7 @@ setup(
     packages=packages,
     package_data={'': ['LICENSE']},
     package_dir={'colout': 'colout'},
+    scripts=['bin/colout'],
     include_package_data=True,
     install_requires=requires,
     license=open('LICENSE').read(),