Move io methods to helper class

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1628655 13f79535-47bb-0310-9956-ffa450edef68
Move io methods to helper class

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1628657 13f79535-47bb-0310-9956-ffa450edef68
Correct method name

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1628658 13f79535-47bb-0310-9956-ffa450edef68