title: GWT - celltable with simple pager issue
body: <p>The cell table pagination is behaving weirdly. check the example from GWT
  <a href="http://gwt.google.com/samples/Showcase/Showcase.html#!CwCellTable" rel="noreferrer">http://gwt.google.com/samples/Showcase/Showcase.html#!CwCellTable</a></p>
  
  <p>The page size here is defined as 15. This is the problem- </p>
  
  <ol>
  <li>click on last page button. Results for 241 to 250 are shown.</li>
  <li>Now click on previous button - results from 226-240 are shown.</li>
  <li>Now click on next button ( this is where the problem is). It showns results from 236 to 250. Whereas it should have displyed 241-250.</li>
  </ol>
  
  <p>I am having same issue in my project.
  Is there any fix for this ??</p>