Mercurial 2020.1.0a22.2714 - rev e3b3f7fcc2f1

Move TextureCombiner class to proper namespace and add doc. (#5237)

* Move TextureCombiner class to proper namespace and add doc.

* fix texture -> Texture and typos

* Asked changes

29: https://github.com/Unity-Technologies/ScriptableRenderPipeline/pull/5237#discussion_r355450409
30: https://github.com/Unity-Technologies/ScriptableRenderPipeline/pull/5237#discussion_r355456645
58: https://github.com/Unity-Technologies/ScriptableRenderPipeline/pull/5237#discussion_r355455688
59: https://github.com/Unity-Technologies/ScriptableRenderPipeline/pull/5237#discussion_r355455828
60: https://github.com/Unity-Technologies/ScriptableRenderPipeline/pull/5237#discussion_r355456239
71: https://github.com/Unity-Technologies/ScriptableRenderPipeline/pull/5237#discussion_r355456391
116: https://github.com/Unity-Technologies/ScriptableRenderPipeline/pull/5237#discussion_r355452421
118: https://github.com/Unity-Technologies/ScriptableRenderPipeline/pull/5237#discussion_r355458846
202: https://github.com/Unity-Technologies/ScriptableRenderPipeline/pull/5237#discussion_r355453832
204: https://github.com/Unity-Technologies/ScriptableRenderPipeline/pull/5237#discussion_r355454334

jpg are not valid in packge, convert to png (#5192)

bump version to 7.1.5, fixed changelog merges

Universal/backports (#5012)

backport of #4976

 updated changeling dates.