Description of problem:
When change message filter options, it is expected that editor open state should not be changed.

That is, if no editor is opened when switching from "Translated" to "Need
Review", the editors should be still closed after switch.

Version-Release number of selected component (if applicable):
Zanata version 1.6.0-alpha-1 (20120419-0011).


How reproducible:
Always

Steps to Reproduce:
1.Find a document that is multiple-paged contains empty, fuzzy, and approved
translation
   Or find a related empty document, with 
   1, 2 and last entries are approved
   3, 5 entries are fuzzy
   the rest are empty.

2. Uncheck all the Message Filter options
3. Check the Message Filter option "Translated" 
4. Ensure every cell editors are closed. If not, close them by clicking "Cancel"
5. Uncheck the Message Filter option "Translated" 
6. Check the Message Filter option "Need Review" 
  
Actual results:
One editor is opened.

Expected results:
Editors should keep closed.

Additional info: