Feature trisolve

[ndellingwood]

sptrsv: Kokkos-based sparse trisolve routines

Initial commit with sparse triangular solve handle, symbolic, and solve routines + ETI infrastructure.

All components are in Experimental namespace as changes will occur while capability is under development.

[ndellingwood]

Spot-check results run on kokkos-dev-2:

Running on machine: sems
Going to test compilers:  gcc/5.3.0 gcc/7.2.0 intel/17.0.1 clang/3.9.0 cuda/9.2
Testing compiler gcc/5.3.0
Testing compiler gcc/7.2.0
Testing compiler intel/17.0.1
  Starting job gcc-5.3.0-OpenMP-release
  Starting job gcc-7.2.0-Serial-release
  PASSED gcc-5.3.0-OpenMP-release
Testing compiler clang/3.9.0
  Starting job intel-17.0.1-OpenMP-release
  PASSED gcc-7.2.0-Serial-release
Testing compiler cuda/9.2
  Starting job clang-3.9.0-Pthread_Serial-release
  PASSED intel-17.0.1-OpenMP-release
  PASSED clang-3.9.0-Pthread_Serial-release
  Starting job cuda-9.2-Cuda_OpenMP-release
  PASSED cuda-9.2-Cuda_OpenMP-release
  Starting job cuda-9.2-Cuda_Pthread-release
  PASSED cuda-9.2-Cuda_Pthread-release
  Starting job cuda-9.2-Cuda_Serial-release
  PASSED cuda-9.2-Cuda_Serial-release
#######################################################
PASSED TESTS
#######################################################
clang-3.9.0-Pthread_Serial-release build_time=198 run_time=395
cuda-9.2-Cuda_OpenMP-release build_time=447 run_time=288
cuda-9.2-Cuda_Pthread-release build_time=421 run_time=366
cuda-9.2-Cuda_Serial-release build_time=427 run_time=369
gcc-5.3.0-OpenMP-release build_time=165 run_time=105
gcc-7.2.0-Serial-release build_time=141 run_time=189
intel-17.0.1-OpenMP-release build_time=325 run_time=105
#######################################################
FAILED TESTS
#######################################################

[srajama1]

@ndellingwood : Thanks for taking care of the changes requested.