Disable 'Syntax Highlighting' and 'Show Full File' on big files

If the file is huge, we disable these features.  A tooltip tells
the user why they cannot access them.

Change-Id: Icec1857844d62456c7abfd8b0d3dd753198330dd
Signed-off-by: Shawn O. Pearce <sop@google.com>

gerrit-gwtui/src/main/java/com/google/gerrit/client/patches/PatchScreen.java

@@ -447,6 +447,7 @@ public abstract class PatchScreen extends Screen implements
       contentTable.finishDisplay();
     }
     showPatch(hasDifferences);
+    settingsPanel.setEnableSmallFileFeatures(!script.isHugeFile());
     settingsPanel.setEnabled(true);
     lastScript = script;