Enable parsing of IPv6 form addresse (see rfc2373 and rfc2732).

This also wraps the 'domain' component in toString with [...], if it
contains any ':' characters.

BUG=
R=floitsch@google.com, sgjesse@google.com

Review URL: https://codereview.chromium.org//14753005

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/stack_trace@22228 260f80e4-7a28-3924-810f-c04153c831b5