small script example addition
rejigged autogenerated images to work with new approach to commands

- updated INSTALL script to do the simpler approach, reading the whole py file rather than trying to pass the cmds about as a string arg
- added a couple of new examples for the layouts section
- NOTE: most of these fail due to #477
Merge branch 'docsWIP' of https://github.com/bentoogood/gaffer into docsWIP