workaround for compiler error in hair module
added flag that allows setting ispc addressing to 64 bit
Merge branch 'devel' of https://github.com/embree/embree
proper typecasts for 64-bit constants
more verbose error if binning runs into issues
Merge branch 'devel'
merge
removed conflict
Merge branch 'devel'
Merge branch 'master' of https://github.com/embree/embree
Color4 constructor from Col3c, set alpha to 1.

Color4 constructor from Col3c initialized the fourth component to 1/255.
This is unintuitive and inconsistent with the overloaded constructor
from Col3f, which initializes the fourth component to 1.0.
updates:
exp code
Merge branch 'master' into devel
merge from master