Revert removing of open_ended after top level plain scalar

[perlpunk]

See also issue #60

This reverts commit 56400d9.

Currently tests will fail because we have the yaml-test-suite with very strict
tests that check for explicit document start/end markers.

So the following tests need to be skipped for now: 27NA 35KP 4V8U 9KAX P76L

The problematic case was that it created the following YAML:

--- foo
%YAML 1.1
--- bar

But you would need ... after `foo' here. Only when quoted you can leave out the end marker:

--- "foo"
%YAML 1.1
--- bar

In YAML 1.2 you always have to add the end marker, so I think it's a good thing.

But I know that the end marker also gets added to cases where it is not needed. Maybe I can have a look into that.

[perlpunk]

@ingydotnet Could you add 27NA 35KP 4V8U 9KAX P76L to the emitter test skip list? (Or remove them from the test whitelist)
And when doing that, maybe you can also change the test-suite to fetch the yaml-test-suite data release instead of a commit id?

[LocutusOfBorg]

can you please also apply the second part of the patch on #60?

[perlpunk]

@LocutusOfBorg yeah, I was looking at it. Funnily I read this issue only after I searched for the cause of the test failures myself =)

I have to first run a whole lotta tests on it, with pyyaml, with perl's YAML::LibYAML, and yaml-test-suite, to make sure it isn't breaking something else.
Not sure how far I can get today...

[perlpunk]

I added the patch, thanks @jrtc27

@ingydotnet the tests are passing again, no need to skip them.
Also YAML::LibYAML tests are all passing again.
pyyaml tests are also passing, although they were already passing for me without the patch from @jrtc27

As a side note:
I can actually think of cases where I would want to add the trailing ..., but these have different conditions.
For example if you have this stream:

foo: |+
  a
  b

...

Then the document-end marker should be emitted, even if not requested, because the exact number of trailing lines needs to be preserved.
I should create a new issue for that.

[jrtc27]

You missed the 7 on my username for the second commit :)

[perlpunk]

@jrtc27 oops, will fix it ;-)
I'll let appveyor finish its tests first though

[perlpunk]

fixed typo and force pushed

[ingydotnet]

Applied. Pushed. Thanks!