Added: Now using _WinAPI_QueryPerformanceCounter() instead of TimerInt(), though only if _WinAPI_QueryPerformanceFrequency() is greater than zero. If it isn't then TimerInt() is used as a backup.
Added: Stopwatch_ElapsedTicks()
Added: Unique signature. (Thanks D4RKON3)
Changed: Return of IsRunning to Null if not a valid Stopwatch handle. (Thanks D4RKON3)
Changed: Used SharpDevelop's ILSpy to look at the code for the Stopwatch class and mimic what Microsoft was doing.