format
Update GAE to 1.9.9
don't need appengine-api-labs dependency
Update GWT to 2.6.1
Update org.slf4j to 1.7.7
Remove maven-dependency-plugin
Remove m2e pluginManagement rules
Update maven-eclipse-plugin config
Update maven-surefire-plugin to 2.17
Update maven-compiler-plugin to 3.1
Update gwt-storage to 1.2.0
Update to Objectify 5.0.3
Update objectify-gwt to 1.2