Test multiline log messages in the regression suite.
Test multiline log messages in the regression suite.

Patch by: Vivek C. <vivek@collab.net>
From issue #2300.

* subversion/tests/clients/cmdline/log_tests.py
 (guarantee_repos_and_wc): Use multiline log messages for
 even-numbered commits.
 (parse_log_output): Store the log message lines in the hash under the
 new key 'lines'.
 (check_log_chain): Check the log message here.
 (log_through_copyfrom_history): Use multiline log messages here.

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