Replace float/UInt64 durations by a more precise Time class (#388)

Improve Clock class with atomic RestartIfOver method and allows to choose required precision

src/Nazara/Core/Posix/TimeImpl.cpp

@@ -0,0 +1,31 @@
+// Copyright (C) 2022 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Core module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Core/Posix/TimeImpl.hpp>
+#include <time.h>
+#include <Nazara/Core/Debug.hpp>
+
+namespace Nz
+{
+	bool InitializeHighPrecisionTimer()
+	{
+		return true; //< No initialization required
+	}
+
+	Time GetElapsedNanosecondsImpl()
+	{
+		timespec time;
+		clock_gettime(CLOCK_MONOTONIC, &time);
+
+		return Time::Seconds(time.tv_sec) + Time::Nanoseconds(time.tv_nsec);
+	}
+
+	Time GetElapsedMillisecondsImpl()
+	{
+		timespec time;
+		clock_gettime(CLOCK_MONOTONIC, &time);
+
+		return Time::Seconds(time.tv_sec) + Time::Nanoseconds(time.tv_nsec);
+	}
+}