Simplify .classpath

* Remove bogus constraint restricting JRE container to 1.6
* Retarget class output folder according to eclipse's suggestion, removes explict version name from the path
Update GAE version

* Latested version is 1.9.6
Merge pull request #247 from curtisullerich/maven_jre_appengine_version_updates

Maven jre/appengine version updates