z2-Environment

Add to 2.6 documentation.

Javadoc says:

/** 
     * The jars that qualify for meta-data parsing can be limited in Jetty. In z2 the default is defined by the
     * regular expression "(?!.+-sources\\.).*\\.jar$" (as Java string) which is all Jars except the source code jars (by convention). 
     * (See also <a href="http://www.eclipse.org/jetty/documentation/9.1.1.v20140108/configuring-webapps.html#container-include-jar-pattern">the Jetty Documentation</a>)
     */