Revert "Expose RevisionInfo to panel extension points"

This reverts commit afe59c7a66.
This change broke the "diff against" drop down, see issue[1].

[1]https://code.google.com/p/gerrit/issues/detail?id=3998

Change-Id: I24aa1e09f9e35bc8a3322ca4bf182367128f65a1

gerrit-gwtui-common/src/main/java/com/google/gerrit/client/GerritUiExtensionPoint.java

@@ -34,6 +34,6 @@ public enum GerritUiExtensionPoint {
   PROJECT_INFO_SCREEN_TOP, PROJECT_INFO_SCREEN_BOTTOM;
 
   public enum Key {
-    ACCOUNT_INFO, CHANGE_INFO, PROJECT_NAME, REVISION_INFO
+    ACCOUNT_INFO, CHANGE_INFO, PROJECT_NAME
   }
 }