Add speaker presentations

Presentations for:

* kalligas
* lovell
* smith
* witek - kroger
* ramirez
* shaughnessy
* noria
* bussink
* koichi
Add presentation links and pdf in speakers data
Add presentation links in speakers bio
Merge branch 'presentations'
Add video links in speakers data
Add video links in speakers bio
Merge branch 'videos'
Add link to speakers page from the schedule
Justify talk description in schedule
Mark keynote speakers in the schedule
Add speaker presentation links in schedule
Add video links in schedule
Merge branch 'schedule'
Rebuilding the website

* Add video links in speakers and schedule
* Add presentation links in speakers and schedule
* Add links from schedule to speaker