examples, alternative namespaces : Part2 of put alternative namespace definitions in local headers.

examples, clcpp_response,alternative_namespaces::clcpp_response : use fmt functions for showing precision of quantities
examples, alternative namespaces : combined the alternative namespace quantity typedefs in header files.
examples, alternative namespaces : add simple timer example

example/alternative_namespaces/timer.cpp

@@ -0,0 +1,35 @@
+
+#include <iostream>
+#include "./timer.h"
+
+/*
+   simple timer, useful for perf timing etc
+*/
+
+using namespace units::experimental;
+using namespace units::si::literals;
+
+int main()
+{
+   std::cout << "Simple timer using mpusz/units ...\n";
+
+   auto const period = 0.5q_s;
+   auto const duration = 10 * period;
+
+   timer t;
+
+   auto const start_time = t();
+
+   std::cout << "Started at " << start_time <<'\n';
+
+   auto prev = start_time;
+   for (auto now = t(); (now - start_time) < duration; now = t() ) {
+      if ( (now - prev ) >= period ){
+         prev = now;
+         std::cout << "tick (" << now << ")\n";;
+      }
+   }
+   t.stop();
+
+   std::cout << "finished at " << t() << '\n';
+}