added support for user options in sx renderer
added support for multiple repeated shading grids
Removed conflicting parameter type warning for coshaders

This was generating reams of spurious warnings in large coshader networks
Merge pull request #240 from davidsminor/sxRendererFixes

Sx renderer fixes
Refactored IECore::StandardRadialLensModel and tidied the comments.
Simplified the arithmetic and refactored it so that it matches that of the paper it is implemented from.
Merge pull request #241 from goddardl/LensModelRefactor

Refactored IECore::StandardRadialLensModel and tidied the comments.
Updating changes and bumped minor version
Fixes crash when merging CortexPrimitives in Houdini 13.

Added merge constructor and fixed signature of stashed() for H13
Merge pull request #242 from andrewkaufman/mergeConstructor

Fixes crash when merging CortexPrimitives in Houdini 13.
Fixed a bug where the EXRImageReader would interpret Deep EXRs as valid.
Merge pull request #244 from goddardl/EXRImageReaderBug

Fixed a bug where the EXRImageReader would interpret Deep EXRs as valid.
Fixed linking of IECoreNuke for Nuke 8.

The libDDImage in Nuke 8 links against libRIPFramework, so that library must be available at build time in order for the configure tests to pass. The -L flag isn't used when searching for the dependencies of a library, so we use the -rpath-link flag to specify where libRIPFramework is to be found.

Unlike the -rpath flag, -rpath-link only has effect at compile time, and doesn't affect linking at runtime.
Added IECore::EXRDeepImageReader and test cases.
Modified the SConstruct so that the EXRDeepImageReader is only built with OpenEXR versions that support deep images.
Changed the EXRImageReader to fail when trying to load a deep exr.
Added IECore::EXRDeepImageWriter and it's bindings and test cases.
Merge pull request #252 from johnhaddon/nuke8

Fixed linking of IECoreNuke for Nuke 8.
Implemented some transformation matrix features

Including coordinateSystem()
SXRenderer now only has a world transform
Merge pull request #248 from davidsminor/sxRendererFixes2

Sx renderer fixes2
Moved the EXRDeepImageWriter compression options into their own scoped binding.
Removed a duplicate test case.