First version of the clamp node
Setting defaults in plug constructors
Using the recommended method of comparing the ancestor of the input to the plug
Updating to use iterators, updating testing logic to be more clear
switching to use isAncestorOf as suggested, in order to avoid the ancestor call which apparently can trigger an evaluation through python
adding a doxygen comment and fixing some tabbing issues
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