Tao now uses _Pragma over #pragma

See merge request !3

This is needed so that the macros expand to pragma's properly
with all compilers

Suppress more places where nvcc can warn about host/device

See merge request !2

Tuple: fix MSVC compiler check conditional

See merge request !1

MSVC2017 gets confused about `tuple_value::get()` (an impl detail)
and `tao::get<T>(tao::tuple)`, which is public API. Renamed the
former to get_value to resolve the issue.

The new version fails to resolve tao::get<T>(const Tuple<...>&). This
older implementation still works though.

GCC 7.3.1 wasn't recognizing this, saying it was deleted due to the
presence of a move assignment operator when really the rvalue-ref
assignment operator should function as both.

MSVC2015 is not compatible with taocpp/tuple. This simple recursive
implementation is used as a fallback.

Add missing CUDA host/device suppressions.

Annotate functions for CUDA.