As a followup to some recent logging changes in the tests, write a custom Formatter in order to have "short" loglevel indicators.
As a followup to some recent logging changes in the tests, write a
custom Formatter in order to have "short" loglevel indicators.

This also takes some care to insert safeguards against code attempting
to use the logging module *before* we have had a chance to configure it.

* subversion/tests/cmdline/svntest/main.py:
  (logger): set to None to catch early-usage in this module
  (class AbbreviatedFormatter): a Formatter subclass to define a
    "levelshort" substitution value for format strings
  (execute_tests): set up the LOGGER global, and configure the root
    logger after we have parsed the options.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion