[Feature request]: connect & login using full ftp url

[Jimmy Wärting]

It would have been nice to get rid of 4 variables and replace them with one url string

client.connect_n_login('ftp://user_name:password@hostname:21')
// or 
client = new Client('ftp://user_name:password@hostname:21')

URL constructor could be used to parse the url...

[Patrick Juchli]

Keeping API as simple and stable for now.