Add High DPI awareness

[pkulchenko]

Steve, it would be great to enable high DPI awareness support by adding GetProcessDpiAwareness and SetProcessDpiAwareness. There are also relevant constants.

From the documentation: "We recommend that you use the application manifest because that sets the DPI awareness level when the application is launched." I tried to implement it by enabling dpi awareness in the manifest, but it generated "application failed to start because its side-by-side configuration is not correct", so the API call is the only choice I have. Here is the manifest change (just in case someone is interested).

  <asmv3:application>
    <asmv3:windowsSettings xmlns="http://schemas.microsoft.com/SMI/2011/WindowsSettings">
      <dpiAware>true</dpiAware>
    </asmv3:windowsSettings>
  </asmv3:application>