hupa org.eclipse.jdt.core.javabuilder com.google.gdt.eclipse.core.webAppProjectValidator com.google.gwt.eclipse.core.gwtProjectValidator org.maven.ide.eclipse.maven2Builder org.maven.ide.eclipse.maven2Nature org.eclipse.jdt.core.javanature com.google.gwt.eclipse.core.gwtNature com.google.gdt.eclipse.core.webAppNature