More robust server specification

Also support a `beanstalk://` scheme URL for server specifications, so connecting to beanstalk servers via IPv6 literals work when listed in `config.php`.  Resolves https://github.com/ptrofimov/beanstalk_console/issues/59
This commit just added a newline on the end of the file (I must have saved it in vim while perusing it). I can only assume that these are intended to be there by whoever has authority over this repo.