rearranged a number of the source image locations. started adding some hand grabbed ones.

also added small bit about the script editor for any one with some hacking needs.
been advised that this is better style for protecting vars
couple of teeny tweaks to styling

- one to make sure bullet lists are using the same text colour as the paragraph text
- another to handle tt text in the same way as 'code' (but a bit bigger). looks like newer asciidoc (on my laptop) tags inline `text`as tt rather than code
some instructions for creating connections
adding image for nodeGraph docs - tooltip pop-up
fixing up some display gack manually in gimp
some fixes and extra content in the noodles section
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
changes to dynamically generated node reference

- restructured script to mirror the dynamicContentGenerators in the GafferUserGuide
- added check for import errors. lack of arnold was causing script to bomb out
sys.path has the cwd on it, so is picking up the Gaffer*.* files

skip it!
better handling of license blocks
indentation fix
fleshing out the text some more
misc subedting fixes and extra lines here and there
started quickstart tutorial, added some screengrabs to accompany it
adds new licenses doc file

* replaces licenses section of the user guide appendix
* small tweak to style sheet to have the raw 'code' blocks look better
some notes about setting up 3rd party renderers
making proper like