Handle MultiMarkdown-style citations.


This is a borrowed idea[p. 23][#Doe:1996].

> This is a cited blockquote without a page reference.[][#Smith:2005].

And a plain paragraph.


And a code block that is not a citation:

	This is not a citation[p. 5][#Doe:1996].


And a work by Johnson that is not cited, but should be included in bibliography:
[Not cited][#Johnson:1996]

And multiple citations.[p. 3][#Doe:1996][p. 10][#Smith:2005]

How about a citation within a footnote? [^footcite]

[#Smith:2005]:	James Smith. Some interesting paper. *Some Journal*, 1(2): 101-123, 2005.

[#Doe:1996]:	John Doe. *Some Book*. Blog Books, 1996.

[#Johnson:1996]:	Bill Johnson. *Some Book*. Blog Books, 1996.

[#James:1996]:	John James. *Some Book*. Blog Books, 1996.

[^footcite]: As described previously. [p. 12][#Smith:2005]