Fixed Echo bug with attr only being resolved on itself.

web-views/sketching/echoElement.wvc

@@ -1,4 +1,4 @@
 ---
 import groowt.view.web.lib.Echo
 ---
-<Echo greeting=${cliGreeting}><p>$greeting</p></Echo>
+<Echo><p>$cliGreeting</p></Echo>

web-views/src/main/groovy/groowt/view/web/lib/Echo.groovy

@@ -15,8 +15,12 @@ class Echo extends DelegatingWebViewComponent {
     Object getProperty(String propertyName) {
         try {
             return super.getProperty(propertyName)
-        } catch (MissingPropertyException ignored) {
-            return attr[propertyName]
+        } catch (MissingPropertyException missingPropertyException) {
+            if (this.attr.containsKey(propertyName)) {
+                return this.attr[propertyName]
+            } else {
+                throw missingPropertyException
+            }
         }
     }