Moving headers into include/sls (#212)

slsSupportLib/include/sls/TimeHelper.h

@@ -0,0 +1,22 @@
+#pragma once
+#include <chrono>
+
+#include "sls/TypeTraits.h"
+namespace sls {
+namespace time {
+using ns = std::chrono::nanoseconds;
+using us = std::chrono::microseconds;
+using ms = std::chrono::milliseconds;
+using s = std::chrono::seconds;
+
+// Absolute value of std::chrono::duration
+template <class Rep, class Period>
+constexpr std::chrono::duration<Rep, Period>
+abs(std::chrono::duration<Rep, Period> d) {
+    return d >= d.zero() ? d : -d;
+}
+
+static_assert(sizeof(ns) == 8, "ns needs to be 64bit");
+
+} // namespace time
+} // namespace sls