Added support in IECoreNuke::DeepImageReader for ZBack channels.
Updated the SConstruct to enable the use of Deep EXR with IECoreNuke.
Added a test case that checks that the IECoreNuke::DeepImageReader correctly adds the ZBack channel if one does not exist.
IECoreMaya::MayaScene now outputs scene:visible
fixed some issues with scene:visible one ieSceneShapes
Initializing the m_mode member within the constructor.
Fixed an uninitialized member in IECore::DeepPixel that could cause undefined behaviour when adding new samples.
Fixed a bug in a sanity check in SHWDeepImageWriter.
Merge pull request #273 from goddardl/coverity

Minor fixes for issues highlighted by Coverity.
Merge pull request #243 from goddardl/NukeDeepReaderBack

Added support in IECoreNuke::DeepImageReader for ZBack channels
Merge pull request #272 from davidsminor/mayaSceneVisibility

Maya scene visibility
added SceneInterface::visibilityName = scene:visible
python binding for SceneInterface.visibilityName
Merge pull request #275 from davidsminor/sceneVisibleAttribute

added SceneInterface::visibilityName = scene:visible
Rewrote TestSceneCache to use parallel_reduce.

This fixes an issue where task.errors() was not returning a meaningful result. Now it returns the sum of all errors on all threads. I verified that without the fixes from 030e7c936de091e22564acec4bbffcb222154286 the test still gets the seg fault, and with those changes it passes.
Fixing seg fault when attempting to read a non-existant attribute several times.

This issue was introduced by 030e7c936de091e22564acec4bbffcb222154286
Merge pull request #277 from andrewkaufman/rootAttrCrash

 Fixing seg fault when attempting to read a non-existant attribute several times