Merge pull request #289 from Carreau/clean-annotate-2

Add a div with cython class for embedding
line-highlight fix + pygments highlight

- fix line highlight that was 1 off
- when pygments available, try to highlight
- when lines have no generated code, do not genera the subdiv and do not
  make clickable
- line number with at least 3 digit for alignment of code
- line that can be expanded with + in front