Part of fix for [HER-1725] on engine page, 'create new job' form gives NPE

* Engine.java
  made protected getProfileCxmlResource() for clear testability
* EngineTest.java
  added testGetProfileCxmlResource()

engine/src/test/java/org/archive/crawler/framework/EngineTest.java

@@ -0,0 +1,11 @@
+package org.archive.crawler.framework;
+
+import org.archive.util.TmpDirTestCase;
+
+public class EngineTest extends TmpDirTestCase {
+    
+    public void testGetProfileCxmlResource() {
+        assertNotNull(new Engine(getTmpDir()).getProfileCxmlResource());
+    }
+
+}