echo-server: adding a simple echo server.

extra/echo-server/authors.txt

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+John Benediktsson

extra/echo-server/echo-server.factor

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+! Copyright (C) 2012 John Benediktsson
+! See http://factorcode.org/license.txt for BSD license.
+
+USING: accessors kernel io io.encodings.ascii io.servers ;
+
+IN: echo-server
+
+: echo-loop ( -- )
+    readln [ write "\r\n" write flush echo-loop ] when* ;
+
+: <echo-server> ( port -- server )
+    ascii <threaded-server>
+        swap >>insecure
+        "echo.server" >>name
+        [ echo-loop ] >>handler ;
+
+: echod ( port -- server )
+    <echo-server> start-server ;
+
+: echod-main ( -- ) 1234 echod drop ;
+
+MAIN: echod-main
+