Populate example list exclusively via javascript.

This removes the duplicate logic for populating examples on first load.
Add demo3-specific examples
Allow Examples page to return different subsets of results
Create a demo3 page with different example queries
remove unused code
Show where the dataset comes from in tooltip
Support new backend api in fragment overview
Avoid fill of lines when hovering
Use new api style data that is more compact but omits values with no workers working
Fix graph style in latest chrome
Replace data in fragment viz with more detailed data when zooming
Only show fragment viz for range where we have data
Use query range in fragment overview and don’t communicate between graphs any more
Merge from origin/master
Update sigma-clipping example
update raco with bugfixes
Fix the fragment viz to use the new api
Better time formatting for 0
Style
Use integer fragment id, improve time format after feedback, visualize