Add support for the JCR multi-valued property.

Regarding to the issue at Camel User Forum as [[camel-jcr] The trouble about the JCR multi-valued property when using JCR_GET_BY_ID](http://camel.465427.n5.nabble.com/camel-jcr-The-trouble-about-the-JCR-multi-valued-property-when-using-JCR-GET-BY-ID-td5757029.html). Here is a fixing.