Alternative packaging by changing the build without source moves

Alternative pull request to #25.
This addresses the requested changes of #19 and #22 to provide a WAR overlay as well as an installable JAR without altering the basic project layout so that it continues to conform to the existing AMP project standard. The additional artifacts are provided with special classifiers "installable" and "overlay" and can be used instead of the regular AMP result.

The only source moves contained in this request are for incorrectly rooted source files due prior merges from a branch of jgoldhammer (due to use of ANT?).