Blender Git Loki

Cycles: Refactor Image Texture limits.

Instead of treating Fermi GPU limits as default,
and overriding them for other devices,
we now nicely set them for each platform.

* Due to setting values for all platforms,
we don't have to offset the slot id for OpenCL anymore,
as the image manager wont add float images for OpenCL now.

* Bugfix: TEX_NUM_FLOAT_IMAGES was always 5, even for CPU,
so the code in svm_image.h clamped float textures with alpha on CPU after the 5th slot.

Reviewers: #cycles, brecht

Reviewed By: #cycles, brecht

Subscribers: brecht

Differential Revision: https://developer.blender.org/D1925