Colorize Neutron log output and refactor log setup code

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
diff --git a/lib/neutron b/lib/neutron
index 5664ff2..4a3d1b0 100644
--- a/lib/neutron
+++ b/lib/neutron
@@ -534,6 +534,11 @@
         iniset $NEUTRON_CONF quotas quota_security_group_rule -1
     fi
 
+    # Format logging
+    if [ "$LOG_COLOR" == "True" ] && [ "$SYSLOG" == "False" ]; then
+        setup_colorized_logging $NEUTRON_CONF DEFAULT
+    fi
+
     _neutron_setup_rootwrap
 }