Disable schema checking by default

Far too many SharePoint responses fail validation in meaningless ways.
diff --git a/src/com/google/enterprise/adaptor/sharepoint/SharePointAdaptor.java b/src/com/google/enterprise/adaptor/sharepoint/SharePointAdaptor.java
index feb9bff..9153e0b 100644
--- a/src/com/google/enterprise/adaptor/sharepoint/SharePointAdaptor.java
+++ b/src/com/google/enterprise/adaptor/sharepoint/SharePointAdaptor.java
@@ -309,7 +309,11 @@
     // When running on Windows, Windows Authentication can log us in.
     config.addKey("sharepoint.username", onWindows ? "" : null);
     config.addKey("sharepoint.password", onWindows ? "" : null);
-    config.addKey("sharepoint.xmlValidation", "true");
+    // On any particular SharePoint instance, we expect that at least some
+    // responses will not pass xml validation. We keep the option around to
+    // allow us to improve the schema itself, but also allow enable users to
+    // enable checking as a form of debugging.
+    config.addKey("sharepoint.xmlValidation", "false");
   }
 
   @Override
diff --git a/test/com/google/enterprise/adaptor/sharepoint/SharePointAdaptorTest.java b/test/com/google/enterprise/adaptor/sharepoint/SharePointAdaptorTest.java
index 1645ce8..2055786 100644
--- a/test/com/google/enterprise/adaptor/sharepoint/SharePointAdaptorTest.java
+++ b/test/com/google/enterprise/adaptor/sharepoint/SharePointAdaptorTest.java
@@ -1666,6 +1666,7 @@
 
   @Test
   public void testValidationError() throws Exception {
+    config.overrideKey("sharepoint.xmlValidation", "true");
     adaptor = new SharePointAdaptor(new UnsupportedSiteDataFactory(),
         new UnsupportedUserGroupFactory(),
         new UnsupportedHttpClient(), executor);
@@ -1703,6 +1704,7 @@
 
   @Test
   public void testParseUnknownXml() throws Exception {
+    config.overrideKey("sharepoint.xmlValidation", "true");
     adaptor = new SharePointAdaptor(new UnsupportedSiteDataFactory(),
         new UnsupportedUserGroupFactory(),
         new UnsupportedHttpClient(), executor);