Version 1.1

Changes:

• parse now returns an extra table with parse error locations. This
  is only additional information, the parse behaviour itself hasn't
  changed.
• parse now handles keys before the first section header gracefully,
  returning a parse error instead of erroring.
• save throws a better error if a provided section is not table-like
  (supports indexing and next)
• The io backend will explicitly close a file after writing, not
  waiting for garbage collection. (PR #5, thanks Lukas)

Unit tests were also added. Given the release schedule that shouldn't
catch many bugs, but at least it's something.