config: exit non zero on non-existent config option (issue4247) When running 'hg config no_such_option', hg exited with a zero exit code. This change now exits with a 1 if the config option does not exist.

merge with crew

bookmarks: refer to "the" active bookmark to clarify that there's only one This is a follow-on to 0c6cdbb697d9 that just makes a slight clarification.