Clean up some warnings, and make the CRT ones more relevant
Merge pull request #397 from zrax/warnings

Clean up some warnings, and make the CRT ones more relevant
Use std::atomic_int for hsSafeRefCnt, and move it to hsRefCnt.h/cpp
Replace hsMutex with std::mutex
Replace hsSleep with std::thread::sleep_for
Use C++11 threading for hsEvent, and clean up the API a bit
Convert hsThread to a std::thread implementation
Simplify plDispatch mutexes a bit