0.87.0

UI

Boxes now export all non-hidden plugs for referencing. Prior to this they only exported “in”, “out” and user plugs.
Fixed unwanted plug promotion when nesting Boxes inside Boxes.

Fixed Subtree update problem.
Added enabling/disabling support to SceneTimeWarp and SceneContextVariables.
Added a SceneSwitch node. This can be used to choose between different scene hierarchies.
Added a ShaderSwitch node. This can be used to switch between different shaders being fed into a ShaderAssignment. It is also compatible with RenderMan coshaders, so can be used to switch between different coshaders in a network.

Added a Clamp node
Fixed bug in Display node which caused problems when using multiple Displays at once.
Added ImageTimeWarp, ImageContextVariables and ImageSwitch nodes - these are equivalent to their Scene module counterparts.

Added missing IntrusivePtr typedefs to GafferImage
Added RecursionPredicate to FilteredRecursiveChildIterator. This allows the definition of iterators which automatically prune the recursion based on some condition.
Redefined RecursivePlugIterators so that they do not recurse into nested nodes - instead they just visit all the plugs of the parent node.
Improved Node::plugSetSignal() behaviour. The signal is now emitted for all the outputs of the plug being set in addition to the source plug - otherwise plugSetSignal() could not be used effectively for plugs which had been promoted to Box level.
Renamed SceneContextProcessorBase to SceneMixinBase.

Fixed build for Ubuntu 12.04.
Updated public build to use Arnold 4.1.
Removed OIIO versioning workaround - previously we had to rename the OIIO library to avoid conflicts with Arnold, but since Arnold 4.1 such conflicts no longer exist.
Updated default boost version to 1.51.0.
Added dependenciesPackage build target. This can be used to make a package of prebuilt dependencies to seed a build. from.
Updated default Cortex version to 8.0.0b5.