Footnotes not supported

[ssmccoy]

While footnotes may not have a particularly natural implementation in confluence wiki format, lacking them causes rst2confluence to not work on any documents which employ them.

Reproduction Steps

1. Create a document which uses a footnote, example.rst:

   Example [2]_.

   .. [2] footnote

2. Execute rst2confluence example.rst > example.confwiki.

Expected

example.confwiki is generated.

Observed

Exception: Unknown visit on line None: <footnote_reference: <#text: '1'>>.
Exiting due to error.  Use "--traceback" to diagnose.
Please report errors to <docutils-users@lists.sf.net>.
Include "--traceback" output, Docutils version (0.7 [release]),
Python version (2.7.2+), your OS type & version, and the
command line used.
make: *** [cyclamen.confwiki] Error 1