Added standard python main()

This patch adds the standard python main() and
the requisite test for the script name.

aprsd.py

@@ -323,6 +323,7 @@ def send_email(to_addr, content):
 
 
 ### main() ###
+def main():
   try:
     tn = telnetlib.Telnet(HOST, 14580)
   except Exception, e:
@@ -464,7 +465,6 @@ while True:
             reply = "Unable to find you (send beacon?)"
             send_message(fromcall, reply)
 
-
        # USAGE
        else:
           reply = "usage: time, fortune, loc, weath, -emailaddr emailbody, -#(resend)"
@@ -481,7 +481,9 @@ while True:
        os._exit(1)
 
   # end while True
-
   tn.close()
-
   exit()
+
+
+if __name__ == "__main__":
+    main()