[PATCH] Do not import unused libraries in tests/cmdline scripts

Hello,

Please find attached the patch for review.
Do not import unused libraries in subversion/tests/cmdline scripts.

[[
[in subversion/tests/cmdline]
* autoprop_tests.py
* basic_tests.py
* copy_tests.py
* export_tests.py
* externals_tests.py
* history_tests.py
* lock_tests.py
* log_tests.py
* prop_tests.py
* revert_tests.py
* schedule_tests.py
* stat_tests.py
* svnadmin_tests.py
* svnsync_tests.py
* switch_tests.py
* trans_tests.py
* utf8_tests.py
  Do not import unused libraries.

* diff_tests.py
  Do not import unused libraries.
  (check_diff_output): Use the string itself for replace() function.

* svnlook_tests.py
  Do not import unused libraries.
  (delete_file_in_moved_dir): Use the string itself for strip()
  function.

* update_tests.py
  Do not import unused libraries.
  (update_wc_on_windows_drive): Use the string itself for splitfields()
  function.
]]

PS: Similar patch is necessary for scripts in tests/cmdline/svntest
directory. I'll prepare that patch once this one is reviewed and
committed in repository. Thank you.

-- 
Regards,
Bhuvaneswaran