Fix #144 archetype use source/target 1.7 instead of 1.8 which is required by GWT 2.8
Fix #144 archetype use source/target 1.7 instead of 1.8 which is required by GWT 2.8

gwt-maven-plugin/gwt-maven-plugin,gwt-maven-plugin/gwt-maven-plugin,gwt-maven-plugin/gwt-maven-plugin