Remove pitfall code in URI reconstruction; fix userinfo handling.

* newURI was always getting overwritten under normal circumstances
  (any time there was a / or ? or similar) so isURIEncoded is not
  necessary. Use of getQuery is dangerous, but the value was being
  thrown away. This commit helps ensure it will not be used in the
  future.
* getUserInfo is replaced with getRawUserInfo to prevent premature
  decoding of separators such as ":". This should be the only behavioral
  change.
Merge pull request #80 from timmc/use-raw-accessors

Remove pitfall code in URI reconstruction; fix userinfo handling.