topic: make command names valid as expected, even if ui.strict=true Before this patch, "hg topics" and "hg stack" cause unintentional "unknown command" failure, if ui.strict=true. In such case, "topics [TOPIC]" and "stack [TOPIC]" are required as a canonical name, because synopsis-like string is used as command name pattern of @command annotation for them. This patch also specifies additional "synopsis" for @command annotation, for intentional output in online help of these commands.