[ptx] Updated my tutorials!

[Rob Park]

Hello everybody,

So with the sudden release of autopano-sift 2.0 and enblend 2.0, I 
decided it was time to update my tutorials.

The first tutorial, describing how to install autopano-sift, panorama 
tools, hugin, and enblend, changed the most:

http://rbpark.ath.cx/tutorial-a

The second tutorial, describing how to use these tools, changed very 
little (mainly I just updated the screenshot for autopano-sift and 
removed the warning about how slow it is ;)

http://rbpark.ath.cx/tutorial-b

Let me know what you think, I appreciate your feedback. Especially if 
you find any errors. ;)