gitignore
adding support for relative URI refs and paths; also fixed the capture braces to always include the leading '/' of any absolute path.
note: the current regex (and consequently the URI function/class itself) is quite permissive of incoming input as quite a lot can be parsed as a legal URI (absolute or relative, path only or host all-in)

we provide a 'prelude' and 'postlude' catch bucket too so that URIs hiding in the middle of other input (e.g. whitespace) is extracted and the caller gets to hear about the surrounding bits as well.
added Jasmine tests - derived off the Mocha tests. 3 fail (so did the Mocha equivalents before)