rfc2217: fix escape function (iterate over bytes properly for Python 3 compatibility, fixes #20)
diff --git a/serial/rfc2217.py b/serial/rfc2217.py
index 3ddc33d..a70df5f 100644
--- a/serial/rfc2217.py
+++ b/serial/rfc2217.py
@@ -1007,7 +1007,7 @@
 
         socket.sendall(escape(data))
         """
-        for byte in data:
+        for byte in iterbytes(data):
             if byte == IAC:
                 yield IAC
                 yield IAC