Configuration and compilation errors

This PR fixes cmake configuration and a compile error that I got on my system (Gentoo Linux, g++ 4.8.2).

Changes to CmakeLists.txt remove dependence on hard-coded paths to CUDA and Boost and restrict static linking to Boost libraries to Win32 systems.

Change to args.hpp includes `<cstring>` header where `memcpy()` is declared.

I am not sure these will work universally though, so please take it with a grain of salt.