A few IPython notebooks

I have started to collect together a few IPython notebooks highlighting a few features of Sherpa - in particular the standalone version. They can be found on GitHub at https://github.com/DougBurke/sherpa-standalone-notebooks/ and the current collection contains:

•  A simple fit
•  Writing your own user model
•  An integrated user model
•  How can I plot data and models using the lower-level interface

The first one is the same as referenced in my
How do I use the standalone build of Sherpa to fit my data?
post from last year, but the last three are *new*.

We will soon have a better location for this style of information, as we continue work on our "Open Sherpa" project. Please come along and help out!