add shebang lines to all lib files

With gerrit 2.8, and the new change screen, this will trigger syntax
highlighting in gerrit. Thus making reviewing code a lot nicer.

Change-Id: Id238748417ffab53e02d59413dba66f61e724383

lib/databases/mysql

@@ -1,3 +1,5 @@
+#!/bin/bash
+#
 # lib/databases/mysql
 # Functions to control the configuration and operation of the **MySQL** database backend
 

lib/databases/postgresql

@@ -1,3 +1,5 @@
+#!/bin/bash
+#
 # lib/databases/postgresql
 # Functions to control the configuration and operation of the **PostgreSQL** database backend