This allows fidelity in controlling excerpt (text that shows up when you pin a topic or link to it externally):
```
I am some text
[excerpt]
This is some **custom** markdown that should be the excerpt
[/excerpt]
More text
```
Previous solution relied on DIVs, unfortunately DIVs do not play well,
by design with mixing markdown unless you have a preceding newline eg:
```
<div class='hello'>
this will be treated properly as markdown
</div>
```
This extra newline is not desirable.
I am also considering adding
```
[div class=excerpt]
[/div]
```
This would offer lots of flexibility to themes and plugins that do not want the extra annoying newline.
This commit removes the old evilstreak markdownjs engine.
- Adds specs to WhiteLister and changes it to stop using globals
(Fixes large memory leak)
- Fixes edge cases around bbcode handling
- Removes mdtest which is no longer valid (to be replaced with
CommonMark)
- Updates MiniRacer to correct minor unmanaged memory leak
- Fixes plugin specs
