The steps involved in the various repository tool `scan_for_server` implementations were overcomplicated and ugly. The main command would check the option (which includes the config value), and then failing that, delegate to the repository tool. The repository tools would then check the config value again before scanning any repository-specific storage locations like SVN attributes or P4 counters. This second config step also looked in the `TREES` config key, which was something from extremely early on in RBTools' life and has never been properly documented or expanded upon in the intended ways. This change cleans up the individual tool `scan_for_server` implementations to only perform checking repository-specific methods. The check for the `TREES` config has been moved to the very end of the process as a fallback, and will emit a warning that such a configuration is deprecated and will be removed. Testing Done: - Ran unit tests. - Set up a configuration that used the old `TREES` method and saw the expected warning.