default, reversing the sense and changing the name of the option to
'--notice-ancestry'.
* subversion/clients/cmdline/cl.h
(svn_cl__notice_ancestry_opt): Was svn_cl__ignore_ancestry_opt.
(svn_cl__opt_state_t): Rename 'ignore_ancestry' to 'notice_ancestry'.
* subversion/clients/cmdline/main.c
(svn_cl__options, svn_cl__cmd_table, main): Track renamed option.
* subversion/clients/cmdline/diff-cmd.c
(svn_cl__diff): Track renamed option (and its sense reversal).
* subversion/clients/cmdline/merge-cmd.c
(svn_cl__merge): Track renamed option (and its sense reversal).
* subversion/tests/clients/cmdline/merge_tests.py
(merge_with_implicit_target): Shorten description.
(test_list): merge_similar_unrelated_trees() is no longer expected
to fail.
* subversion/doc/book/book/ch06.xml
* subversion/doc/book/book/ch08.xml
Track the renamed option.
