Fixed Bootil::File::ChangeMonitor not following symbolic links on Windows

Bootil::File::ChangeMonitor fails to monitor changes for subdirectories that are actually symbolic links. This fixes that.

Here's the code that I used to test this on Windows. A symbolic link can be created with ```mklink /D /J "C:\source" "D:\target"``` from the command-line.

```c++
#include <iostream>
#include <windows.h>
#include <Bootil/Bootil.h>

int main()
{
	std::cout << "hi" << std::endl;

	Bootil::File::ChangeMonitor monitor = Bootil::File::ChangeMonitor();

	monitor.WatchFolder("C:\\Program Files (x86)\\Steam\\steamapps\\hullupelaaja\\garrysmod\\garrysmod", true);

	while (true)
	{
		if (monitor.HasChanges())
		{
			std::cout << "(" << Bootil::Time::UnixTimestamp() << ") " << monitor.GetChange() << std::endl;
		}
	}
}
```