Improved shader assignment reporting in SceneInspector.

We now show the name of the node which generated the shader if it is available.

Fixes #335.
Improved shader handle generation.

Handles are now generated in a repeatable fashion, and include the name of the node from which the shader was generated.
Merge pull request #786 from johnhaddon/shaderHandles

Improved SceneInspector shader display and shader handles
Updating changes and bumped patch version
Added GafferScene.PrimitiveVariables node.

This allows arbitrary primitive variables with constant interpolation to be added to objects.
Added a space into the PrimitiveVariables menu item.
Improved PrimitiveVariables node documentation.
Merge pull request #791 from johnhaddon/primitiveVariables

Added GafferScene.PrimitiveVariables node.
Added string matching function.

This is extracted from PathMatcher and will be used as the basis for unifying string matching across Gaffer as required by #707.
Added numericSuffix() function to StringAlgo.h.

This allows us to remove some duplicated code from GraphComponent and BranchCreator.
Added a Duplicate node to GafferScene.
Merge pull request #794 from johnhaddon/duplicate

GafferScene::Duplicate