Clarify Address usage in send example

Improved the script to explain the recipient address a little better.
Changed the address concat to a reference to a specific kind of Iota address.  
This is loosely inspired by the JAVA sen transaction test case.

Author: maeck70

examples/send_transfer.py

@@ -4,6 +4,8 @@
 """
 from iota import *
 
+SEED1 = b"THESEEDOFTHEWALLETSENDINGGOESHERE999999999999999999999999999999999999999999999999"
+ADDRESS_WITH_CHECKSUM_SECURITY_LEVEL_2 = b"RECEIVINGWALLETADDRESSGOESHERE9WITHCHECKSUMANDSECURITYLEVEL2999999999999999999999999999999"
 
 # Create the API instance.
 api =\
@@ -12,7 +14,7 @@
     'http://localhost:14265/',
 
     # Seed used for cryptographic functions.
-    seed = b'SEED9GOES9HERE'
+    seed = SEED1
   )
 
 # For more information, see :py:meth:`Iota.send_transfer`.
@@ -26,8 +28,7 @@
       # Recipient of the transfer.
       address =
         Address(
-          b'TESTVALUE9DONTUSEINPRODUCTION99999FBFFTG'
-          b'QFWEHEL9KCAFXBJBXGE9HID9XCOHFIDABHDG9AHDR'
+          ADDRESS_WITH_CHECKSUM_SECURITY_LEVEL_2,
         ),
 
       # Amount of IOTA to transfer.