Bug 1214616
This patch adds colors to on-screen Neutron log output in the same way nova,
cinder, and heat engine do.
To this aim, colorized logging configuration has been moved to ./functions.
The reason for this refactoring is that these instruction are the same or
very similar for each project, with the only exception of the target
configuration file.
Change-Id: Idf0d1b842bb9ab046c9ef826de1dfc55b3f1df9d