title: Adding new column in sencha grid before the last column
body: <p>Suppose i have a sencha grid which has columns 
  Name, Email, Address, Phone, City, State, Country</p>
  
  <p>Now out this initially i am only displaying Name, Email, Address and Phone.</p>
  
  <p>I have given the provision to display more columns, the pending ones, City, State and Country.</p>
  
  <p>But the problem in that when ever i add a new column in the grid then it gets appended to the last...in my case suppose i add City then it gets appended after Phone...</p>
  
  <p>But i want Phone to always remain the last column and if any other column is added then it should be prefixed before Phone column.</p>
  
  <p>I am using sencha grid.</p>
  
  <p>Kindly suggest</p>