Add IPv6 support in RestTemplate

Prior to this commit, RestTemplate would not would
not accept IPv6 raw addresses in URLs because UriComponentsBuilder
would not parse/encode the Host part correctly.

The UriComponentsBuilder now parses and encode raw IPv6 addresses
in the "[1abc:2abc:3abc::5ABC:6abc]" format and also supports the
use of IPv6 scope_ids (see JDK8 java.net.Inet6Address),
like "[1abc:2abc:3abc::5ABC:6abc%eth0]".

Issue: SPR-10539
Polish

Issue: SPR-10539
Merge pull request #358 from bclozel/SPR-10539

* bclozel-SPR-10539:
  Polish
  Add IPv6 support in RestTemplate
Add NoHandlerFoundException to DispatcherServlet

Prior to this commit, the DispatcherServlet would send an error
response using the HttpServlet API when no Handler was found to
handle this request.

Now the DispatcherServlet can be configured to throw a
NoHandlerFoundException, when the throwExceptionIfNoHandlerFound
property is set to "true".
Those exceptions can be later on caught by default or custom
HandlerExceptionResolvers/ExceptionHandlers.

Issue: SPR-10481
Merge pull request #359 from bclozel/SPR-10481

* bclozel-SPR-10481:
  Add NoHandlerFoundException to DispatcherServlet