CUDA NVCC Build Support

Several issues have been found in the boost modules when building boost headers in CUDA's NVCC compiler. NVCC is a ubiquitous C++ compiler in the field GPGPU computing and boosts applications overlap with CUDA considerably. Support for NVCC in boost build and regression testing would ensure these issues don't continue on the NVCC platform.

boostorg/signals2#53
boostorg/preprocessor#37
ddemidov/amgcl#75

[stale]

Thank you for your contributions. Main development of B2 has moved to https://github.com/bfgroup/b2
This issue has been automatically marked as "transition" to indicate the potential for needing transition to the new B2 development project.