title: Include missing column-values between two Indexs when a GroupBy is run on a DataFrame
body: <p>I have a DataFrame that was GroupBy lineOfBuiness, stream and status and a count column was created. I am trying to get the status column to be consistent in terms of the number of row between to two lineOfBusiness slices (Commodities and Equities Derivatives below). </p>
  
  <p>For example: If you notice in Commodities Slice, there is a status called 
  'Prioritized for Analysis' that does not exist in Equity Derivatives. </p>
  
  <p>Another example: There is a slice 'Prioritized fro Development' in the Equities Derivatives that does not exist in Commodities. Is there anyway to programatically create the missing statuses and assign a count 0 or NaN.</p>
  
  <pre><code>lineOfBusiness            stream            status                             count
      Commodities               BOW/Project       Closed                             2   
                                                  In Analysis                        4   
                                                  In Solution                        3   
                                                  Open                              28   
                                                  Prioritized for Analysis           1   
                                                  Tech Execution                     7  
  
  
  
  Equity Derivatives        BOW/Project       In Analysis                        2   
                                              In Solution                        1   
                                              Open                               4   
                                              Prioritized for Development        1   
                                              Tech Execution                     1   
  </code></pre>