[ptx] Two more new Hugin tutorials

[Bruno Postle]

This first new tutorial from Joachim Fenkes shows how to use d and e
lens shift parameters to stitch a long series of photographs taken
of a mural:

  Creating linear panoramas with Hugin
  http://www.dojoe.net/tutorials/linear-pano/

The second one was prompted by Erik Krause's Perspective Correction
page on the Panotools wiki.  It covers using vertical and horizontal
control points to re-align rectilinear photographs:

  http://hugin.sourceforge.net/tutorials/perspective/

-- 
Bruno