packaging: Added encodingvalidator.sh to validation list

This patch updates encodingvalidator.sh utility and adds
it to the list of executed validators in validatedb.sh
generic script.

Change-Id: Ic89088c7738eb379b2bc88d8d59193d4ed20a295
Bug-Url: https://bugzilla.redhat.com/920565
Signed-off-by: Alex Lourie <alourie@redhat.com>