Allow setext headings with no blank line
inline footnote link
coalescing footnote definition blocks, 1
parser recognizes footnote defs
Parsing and Rendering
back out undesired changes
back out another undesired change
extract footnote handling from block parser
foonote_offset option
remove unused variable warming
Merge pull request #6 from mattly/footnotes

Add initial support for footnotes
Merge in footnote support
add spec driver test
Parse, render multi-paragraph footnotes.

Parsing: FnDef will greedily grab all following indented code.  As far as I can
tell, this conforms to the behavior of pandoc and multimarkdown.

Rendering: If the final block in the footnote is a paragraph, the "return to
article" link will render in that paragraph.  Otherwise, a new paragraph is
appended to the footnote containing the return link.  This mimics pandoc's
behavior -- multimarkdown will append it to the last paragraph of the footnote,
regardless of what follows.
remove warnings
fix hr rendering
Merge pull request #9 from artemeff/hr

Fix hr rendering

(Many thanks. Dave)
failing test for parsed footnote w/o option
Don't parse FnDef blocks unless footnotes enabled

I'm not terribly happy with this solution, since passing the Options struct to
Parser.parse and subsequently Line.type_of is a major signature change.  My
workaround of providing a backwards-compatible signature is also not ideal;
I should go through and fix the many tests that use the two-argument signature
instead.

On the flip side, if Parser produces an FnDef block, but that's never coalesced
into a FnList block by Parser.handle_footnotes, what are we to do?  Not render
the FnDef at all?  Append `[^id]` to the contents first block's first line, and
render the contents?  It seemed to me that simply not parsing the FnDef to
begin with was a simpler choice.

This choice will also allow Line.type_of to ignore, for example, table lines if
desired, or if support for other markdown extensions are added later, to
opt-into their parsing.
Merge branches 'bug/footnotes-when-not-enabled' and 'multi-paragraph-footnotes'