updated README for 3.x

URL constructor parses input

Fix error for toString with no host

Added explicit toHash.

The compiler-provided might work, but I'm a bit leery.

fix resolve() returning wrong result

fix resolve(), toString + ipv6 host

Added more equality operations.

I just noticed I broke part of the implicit string-ness of a URL. Can't fix it, apparently.

fix compilation error

Add sorting and equality operators.

Use URLException for invalid %-enc UTF.