Move to high-resolution timer/counter

 * thus making MDD_realtimeSynchronize actually independet of parameter resolution.
 * and setting minimum supported OS version to WinXP.

The reason is that SimulationX always reported an elapsed time less than the "real-time", e.g. if Modelica_DeviceDrivers.Blocks.Examples.TestInputKeyboard runs for 10s SimulationX reports 7.5s although 10s passed. I needed to adpat the default resolution from 1 to 1000 to get matching results. This is no longer required if high resolution counters are used.

Maybe you want to handle this pull request only as an idea since #42 reported some other severe issues in MDD_realtimeSynchronize. If in future it will be implemented as external object the call of QueryPerformanceFrequency should be moved to the constructor.