hg: jdk/sandbox: 8198656: Update copyright to 2018

[chris.hegarty at oracle.com]

Changeset: b4dd09b5d6d8
Author:    rriggs
Date:      2018-02-23 17:34 -0500
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/b4dd09b5d6d8

8198656: Update copyright to 2018
Reviewed-by: joehw

! src/java.xml/share/classes/com/sun/org/apache/xml/internal/serializer/ToStream.java
! src/java.xml/share/classes/jdk/xml/internal/SecuritySupport.java