- Issue #3300: make urllib.parse.[un]quote() default to UTF-8.

- Issue #3300: make urllib.parse.[un]quote() default to UTF-8.
  Code contributed by Matt Giuca.  quote() now encodes the input
  before quoting, unquote() decodes after unquoting.  There are
  new arguments to change the encoding and errors settings.
  There are also new APIs to skip the encode/decode steps.
  [un]quote_plus() are also affected.