Update URI related documentation and examples.

Update URI related documentation and examples.

Adds a test for all the examples.

Fixes issues: #28659, #28660, #28661

BUG= http://dartbug.com/28659, http://dartbug.com/28660, http://dartbug.com/28661
R=floitsch@google.com

Committed: https://github.com/dart-lang/sdk/commit/d4a1e0689216c6bd013b6f97e0ea255e1f134b9f

[Lasse Reichstein Nielsen, 2017-02-07 10:00:09]

lrn@google.com changed reviewers:
+ floitsch@google.com

[floitsch, 2017-02-07 10:47:15]

LGTM.

https://codereview.chromium.org/2679933002/diff/1/sdk/lib/core/uri.dart
File sdk/lib/core/uri.dart (right):

https://codereview.chromium.org/2679933002/diff/1/sdk/lib/core/uri.dart#newco...
sdk/lib/core/uri.dart:189: * except if the path starts with `\\\\?\\` in which
case
I have no idea how to read this. Is this a regexp?
Probably not, but hard to tell. Are the "\" escaped?
I believe they are, but commonmark doesn't seem to require that.

Please add examples, and make sure that `\` really needs to be escaped.

https://codereview.chromium.org/2679933002/diff/1/sdk/lib/core/uri.dart#newco...
sdk/lib/core/uri.dart:224: * // C%3A
Why this change?

[Lasse Reichstein Nielsen, 2017-02-07 10:54:31]

https://codereview.chromium.org/2679933002/diff/1/sdk/lib/core/uri.dart
File sdk/lib/core/uri.dart (right):

https://codereview.chromium.org/2679933002/diff/1/sdk/lib/core/uri.dart#newco...
sdk/lib/core/uri.dart:189: * except if the path starts with `\\\\?\\` in which
case
Not a regexp, it's the character sequence BACKSLASH-BACKLASH-QUESTION-BACKSLASH.
The `\` is a markdown/commonmark escape, and it allows you to escape meaningful
characters.

I haven't checked that it's also needed in ``-quotes, but it was needed before …
and now I have. Backslashes don't need to be escaped in ``-quotes, so I'll have
to undo that.

https://codereview.chromium.org/2679933002/diff/1/sdk/lib/core/uri.dart#newco...
sdk/lib/core/uri.dart:224: * // C%3A
Because the Uri class changed recently to escape the first colon of a path if it
would look like a scheme (for URIs with no scheme and no authority).

[Lasse Reichstein Nielsen, 2017-02-07 10:54:32]

Description was changed from

==========
Update URI related documentation and examples.

Adds a test for all the examples.

Fixes issues: #28659, #28660, #28661

BUG= http://dartbug.com/28659, http://dartbug.com/28660,
http://dartbug.com/28661
==========

to

==========
Update URI related documentation and examples.

Adds a test for all the examples.

Fixes issues: #28659, #28660, #28661

BUG= http://dartbug.com/28659, http://dartbug.com/28660,
http://dartbug.com/28661
R=floitsch@google.com

Committed:
https://github.com/dart-lang/sdk/commit/d4a1e0689216c6bd013b6f97e0ea255e1f134b9f
==========

[Lasse Reichstein Nielsen, 2017-02-07 10:54:33]

Committed patchset #2 (id:20001) manually as
d4a1e0689216c6bd013b6f97e0ea255e1f134b9f (presubmit successful).