Support for deviantart text expandos

Fixes #1859

Unfortunately deviantART only provides roughly the first paragraph, so this is the best we can get (there didn't seem to be any way to get the full text, unless I missed it).
The ellipsis is added if the last non-whitespace character isn't a period.

![image](https://cloud.githubusercontent.com/assets/7673145/5426177/dd215714-830e-11e4-820d-2604db187424.png)