Add Automatic-Module-Name MANIFEST entry for Java 9 compatibility

In order to make Commons Lang usable in Java 9 module system, we need to add a new entry to the MANIFEST file as a temporary fix before we we can compile on Java 9 and add a module-info.java file.

We had discussions on the ML on how to fix this in parent pom (see http://markmail.org/message/5imtc5q4gsbg4alm), but we haven't reached consensus about how to implement this.