Render issues for header and separator

[iJackUA]

Hi, I have found couple render issues when some tags are not displayed.
Not sure maybe it is wrong Markdown markup, but other parser (I test Ciconia, php-markdown, parsedown and your one) display it as expected

Example 1

# hello, This is Markdown Live Preview

----
## what is Markdown?
see [Wikipedia](http://en.wikipedia.org/wiki/Markdown)

{mycustom_widget}

### Tasks list
- [x] @mentions, #refs, [links](), **formatting**, and <del>tags</del> supported
- [x] list syntax required (any unordered or ordered list supported)
- [x] this is a complete item
- [ ] this is an incomplete item
- [x] @mentions, #refs, [links](), **formatting**, and <del>tags</del> supported


* SHA: 16c999e8c71134401a78d4d46435517b2271d6ac
* User@SHA: mojombo@16c999e8c71134401a78d4d46435517b2271d6ac
* User/Repository@SHA: mojombo/github-flavored-markdown@16c999e8c71134401a78d4d46435517b2271d6ac
* #Num: #1
* User#Num: mojombo#1
* User/Repository#Num: mojombo/github-flavored-markdown#1

Example 2

----

## changelog 1

* 17-Feb-2013 re-design

----
## changelog 2
* 17-Feb-2013 re-design

[cebe]

Thanks for pointing this out! I am aware of this issue but was not sure how or whether to fix it at all. The original specs are not 100% clear about it and there are cases where you do not want this to work.
e.g.

Lorem ipsum dolor sit amet. The company xyz was founded in
1985. After that it grew....

You do not want to have a list started here.

Current implementation expects a blank line between different block elements. Will check how we can fix this.

[samdark]

For the cases mentioned it's all about blank lines after headers. I don't think these are mandatory in this case.

[iJackUA]

@samdark not only header
in first case Header without line break "killed" first line under it
and in second case hr element killed header under it

it is really unexpected behavior
for example from GitHub's markdown manual

# The largest heading (an <h1> tag)
## The second largest heading (an <h2> tag)
…
###### The 6th largest heading (an <h6> tag)

total mess

[samdark]

Well, yeah. HR is the same case where it doesn't make sense to require extra space.

[cebe]

Working on a fix already.

[cebe]

Should all be fixed by 8d035ac. If you encounter more cases like this (even if they pass), please add them to the test file or paste them here.