THRIFT-4478: Thrift will not build with dlang 2.078 or later (#1559)

* THRIFT-4478 Thrift will not build with dlang 2.078 or later

This fixes build errors and deprecation warnings on dmd v2.080.0.

* THRIFT-4478: Update ubuntu-artful docker build image to use DMD 2.080.0

* THRIFT-4478 Fix build failure for nonblocking

* THRIFT-4478: update readme files
diff --git a/lib/d/test/serialization_benchmark.d b/lib/d/test/serialization_benchmark.d
index 35515c8..40d0480 100644
--- a/lib/d/test/serialization_benchmark.d
+++ b/lib/d/test/serialization_benchmark.d
@@ -13,7 +13,7 @@
  */
 module serialization_benchmark;
 
-import std.datetime : AutoStart, StopWatch;
+import std.datetime.stopwatch : AutoStart, StopWatch;
 import std.math : PI;
 import std.stdio;
 import thrift.protocol.binary;
@@ -46,7 +46,7 @@
     }
     sw.stop();
 
-    auto msecs = sw.peek().msecs;
+    auto msecs = sw.peek().total!"msecs";
     writefln("Write: %s ms (%s kHz)", msecs, ITERATIONS / msecs);
   }
 
@@ -64,7 +64,7 @@
     }
     sw.stop();
 
-    auto msecs = sw.peek().msecs;
+    auto msecs = sw.peek().total!"msecs";
     writefln(" Read: %s ms (%s kHz)", msecs, ITERATIONS / msecs);
   }
 }