Blender Git Loki

Update install_deps.sh to OIIO 1.39 and OSL 1.4.0.

Note that I also updated OpenEXR to 2.1.0 (and updated our CMake openexr module as well).

Users will have to update their build settings as told by the script (also in BUILD_NOTES.txt generated file)!

Note I removed all ugly patches from this script, we are currently using custom git repo for OpenEXR/OIIO/OSL,
hopefully we will soon be able to use vanillia code from official repos!