Fix GPU example build failed with cuda 5.5
Update cmake files by using CUDA_CUDA_LIBRARIES
fixed cpp wrappers of ML tree-based models
Ignore Windows' Thumbs.db
Merge pull request #1339 from mdim:ml_cpp_wrappers_fix
Merge pull request #1267 from clhsieh:gpu_example_build_failed_with_cuda5p5
Merge pull request #1341 from roynos:master