Nasty list parsing edge case

[vsemozhetbyt]

See nodejs/node#19647

The list item number in v0.3.6 is 1, in v0.3.19 is 0, but the erroneous list is added in both cases, unlike the GitHub parser behavior.

[styfle]

I was able to reproduce with this:

Example list that does not work.

* First one goes here. We can add a new line here as long as we indent
  and the output will render as if there is no new line.
* But if we start the next line with a number followed by a period such as
  0. Then it will not render properly.

Example list that does work.

* First one goes here. We can add a new line here as long as we indent
  and the output will render as if there is no new line.
* Now if we start the next line to end with a number followed by a period such as 0.
  Then it will render properly.

Marked Demo

I haven't looked at the spec but it seems like this is ambiguous behavior since nested lists are possible.