core: Add validate-on-match to data source

Since JBoss EAP 6.1 connection level validation isn't performed unless
the "validate-on-match" parameter is explicitly set to true. This causes
several issues like connections not being removed from the connection
pool when the database is restarted. This patch adds that parameter to
the data source configuration.

Change-Id: I8f43be1cd95597dbc75ffb6a873a1b1e312c3897
Signed-off-by: Juan Hernandez <juan.hernandez@redhat.com>