Add GPE default GWT nature to the Eclipse .project file

Change-Id: I1d01c589cf6cc58265231dc6d0e43b87564b851b

user/src/com/google/gwt/user/tools/templates/eclipse/.projectsrc

diff --git a/user/src/com/google/gwt/user/tools/templates/eclipse/.projectsrc b/user/src/com/google/gwt/user/tools/templates/eclipse/.projectsrc
index 2436f15..dc8c58a 100644
--- a/user/src/com/google/gwt/user/tools/templates/eclipse/.projectsrc
+++ b/user/src/com/google/gwt/user/tools/templates/eclipse/.projectsrc
@@ -4,12 +4,24 @@
    <comment>@moduleShortName project</comment>
    <projects/>
    <buildSpec>
-       <buildCommand>
-           <name>org.eclipse.jdt.core.javabuilder</name>
-           <arguments/>
-       </buildCommand>
-   </buildSpec>
-   <natures>
-       <nature>org.eclipse.jdt.core.javanature</nature>
-   </natures>
+    <buildCommand>
+      <name>org.eclipse.jdt.core.javabuilder</name>
+      <arguments>
+      </arguments>
+    </buildCommand>
+    <buildCommand>
+      <name>com.google.gdt.eclipse.core.webAppProjectValidator</name>
+      <arguments>
+      </arguments>
+    </buildCommand>
+    <buildCommand>
+      <name>com.google.gwt.eclipse.core.gwtProjectValidator</name>
+      <arguments>
+      </arguments>
+    </buildCommand>
+  </buildSpec>
+  <natures>
+    <nature>org.eclipse.jdt.core.javanature</nature>
+    <nature>com.google.gwt.eclipse.core.gwtNature</nature>
+  </natures>
 </projectDescription>