title: How to get all total for all rows across all pages in a UI-GRID
body: <p>I am trying to display the total sum for a column in my UI-GRID. the problem is that I display 10 rows per page and the ui-grid footer only calculates the total sum for the the rows per page. How do I enable the ui-grid to calculate the total for all the rows in the UI-GRID</p>
  
  <p>I have a created a plunker example to show my issue:
  <a href="http://next.plnkr.co/edit/Gjpt8tw4JpDzl1lG?preview" rel="nofollow noreferrer">http://next.plnkr.co/edit/Gjpt8tw4JpDzl1lG?preview</a></p>