Link URI re: issue 486

The proposed changes address the silent failing of adding a link to an unrecognized URI. They allow the user to correct any potential mistakes made to the initial address through a prompt dialogue. 
Also, generally, you shouldn't change existing code if it doesn't actually change anything. Not sure what your motivation was for changing this. ("ps", btw, stands for "prompt service". "prompts" could stand for the same, but it would be quite odd and ambiguous)