Tvd

- fix: download_as_utf8 converts HTML characters
- feat: IPython Notebook SVG display

- feat(Plugin): give to Caesar what belongs to Caesar
- feat: keep track versions of TVD and its plugins
- feat(Plugin): new download_as_utf8 method takes care of UTF-8 encoding
- feat(AnnotationGraph): floating time relabelling, pre- and post-alignment

- fix: tvd.create argument parsing

- feat: temporally-ordered graph traversal
- feat: timerange estimation
- improve: TStart and TEnd jsonification

- remove requests dependency

- first public release