Colour - HDRI - 0.2.0

Colour - HDRI - 0.2.0 - Alpha Milestone

This release is a compatibility release with Colour 0.4.1.

Support for Python 2.7 has been dropped!

Changes

• The colour_hdri.camera_response_functions_Debevec1997 definition has been updated to support an extrapolating function. It can be used to defined the behaviour over regions masked by the weighting function. (@KelSolaar, @KevinJW)