Support for parsing tables in reStructuredText

[GoogleCodeExporter]

It would be good for pandoc to allow parsing of rST tables. Example (an 
extract from one of my reference pages):

+----------+------+---------------------+
| argument | type | description         |
+==========+======+=====================+
| `val`    | any  | The value to return |
+----------+------+---------------------+

Original issue reported on code.google.com by kierda...@googlemail.com on 10 Jan 2010 at 6:24

[GoogleCodeExporter]

r1840 adds (incomplete) support for RST tables.
colspans and rowspans are still not supported.

Original comment by fiddloso...@gmail.com on 27 Feb 2010 at 6:45