-fixes telnetlib constants to be one-length byte arrays instead of ints

-fixes telnetlib constants to be one-length byte arrays instead of ints
-this fixes telnet negotiation (broken in 3.0)
-merged/ported telnetlib tests from trunk (below)

Merged revisions 71302,71377,71385 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r71302 | jack.diederich | 2009-04-05 22:08:44 -0400 (Sun, 05 Apr 2009) | 1 line

  test the telnetlib.Telnet interface more thoroughly
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  r71377 | jack.diederich | 2009-04-07 16:22:59 -0400 (Tue, 07 Apr 2009) | 1 line

  eliminate more race conditions in telnetlib tests
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  r71385 | jack.diederich | 2009-04-07 19:56:57 -0400 (Tue, 07 Apr 2009) | 4 lines

  - Make timing assertions very generous (a la test_timeout.py)
  - Break the gc cycle in negotiation tests
  - test the different guarantees of read_lazy and read_very_lazy
........