Consolidated config.ocio and nuke_config.ocio into a single config.ocio.

Consolidated config.ocio and nuke_config.ocio into a single config.ocio.
Moved the sRGB output transform to the top of the list of Views. This should now be the default View used in most applications.
Added 'rendering' and 'compositing_linear' roles which default to have the same value as the 'scene_linear' role.
Added the transfer functions and full color space transforms for sRGB, Rec.709, Rec.1886 and Rec.2020.
Added the 'Aliases' colorspaces back into the config.
Fixed an issue that caused some alias colorspaces to be generated incorrectly.
Fixed some alias names that didn't follow the conventions of other alias names.