Error docs and log improvements

Added

• Improve the documentation on Error and ErrorKind and add Error::is_timeout.

Fixed

• Improve connection reuse log message and fix some false positives around its emission. The warning about connection reuse will now point users to the wiki page which explains the message in depth. (#335) @sagebind

Dependency Updates

• Update Public Suffix List to bc5d64d (#328) @teto-bot