Instead of having to leave `**kwargs` "forever" in `salt.config.minion_config` and `salt.config.apply_minion_config` in order to support API access to those which still passes `check_dns`. Support the argument but show a deprecation warning once. Leave the deprecation warning for 2 major releases. Then, finally, and properly, remove `check_dns` for good.
`salt.config.load_config()` cannot be hard-coded to use only the master configuration file as the default configuration file path to know if the user has passed any configuration file in the CLI tool or not.
To fix this, `default_path` was added. This way, the minion config or client config or even the salt cloud config can say which is the expected default path of the configuration file and properly load config from environment variables.
On the parsers cleanup branch, I though about making the available options as equal as possible. Since the log_file setting for the master and the minion could be separately set, I made the logfile option for the key also log_file. Yet, since there's no key specific config file, it shares master, one could only specify the log_file settings from the cli, it could not be hardcoded on the config file, unless, we made a separate config file just for key.
So, in order to reduce required changes, and keep it all as backwards compatible as possible, the key log file options is now, once again, `--key-logfile` which will allow us to hardcode it in the masters config file as `key_logfile`.
This will also, hopefully make travis behave better too.
