alias: prepare for subsection aliases
Switch git_unknown_cmd_config() from skip_prefix() to parse_config_key() for alias parsing. This properly handles the three-level config key structure and prepares for the new alias.*.command subsection syntax in the next commit. This is a compatibility break: the alias configuration parser used to be overly permissive and accepted "alias.<subsection>.<key>" as defining an alias "<subsection>.<key>". With this change, alias.<subsection>.<key> entries are silently ignored (unless <key> is "command", which will be given meaning in the next commit). This behavior was arguably a bug, since config subsections were never intended to work this way for aliases, and aliases with dots in their names have never been documented or intentionally supported. Signed-off-by: Jonatan Holmgren <jonatan@jontes.page> Signed-off-by: Junio C Hamano <gitster@pobox.com>