title: tkintertable data how to update
body: <p>I'm using tkintertable git cloned from github. Basically using the same example as <a href="https://stackoverflow.com/questions/34094475/how-can-i-have-the-tkintertable-tables-columns-sorted-the-way-they-are-in-the-d">the other SO question</a>.</p>
  
  <p>How do you add a raw of data into the table after the tkinter has been in its mainloop? How do you update data in the current table? </p>
  
  <p>In the code below, I added a callback and use a tkinter <code>after()</code> to call. In the callback it tries to add a row to the data model. I also tried directly adding a key/value pair to the <code>data</code> object. Neither of them worked. </p>
  
  <pre><code>from Tkinter import *
  from tkintertable.Tables import TableCanvas
  from tkintertable.TableModels import TableModel
  master=Tk()
  tframe = Frame(master)
  tframe.pack(fill='both')
  data={'1': {'Klasa':'6A', 'E Hene': 1, 'E Marte': 2,'E Merkurre':3,'E Enjte':4,'E Premte':5},
        '2': {'Klasa':'', 'E Hene': 1, 'E Marte': 2,'E Merkurre':3,'E Enjte':4,'E Premte':5}}
  model = TableModel()
  table = TableCanvas(tframe,model=model)
  table.createTableFrame()
  model = table.model
  model.importDict(data) #can import from a dictionary to populate model
  
  def update_data(event=None):
      global data
      global model
      nk = "3"
      print "update_data \n"
      model.addRow(key=nk,
                   Klasa="333")
  master.after(5000, update_data)
  
  master.mainloop()
  </code></pre>