Update Snort binary to version 2.9.5.6 and fix potential bug in Spoink output plugin

Change Log: Snort 2.9.5.6
====================

Date: 01/28/2014
-----------------------

This updates the Snort binary to version 2.9.5.6.  No new features were added, but a potential bug in the Spoink output plugin used on pfSense was fixed. This bug could, in some situations, lead to Snort trying to access the pf (packet filter) device without a valid file descriptor.