Update about page
Add link to slideshow in about page
Update of documentation
Adapt method to detect JMP (numeric) vs NSA vs Glass surveys
Avoid nsa filters creation when user has no rights on it #2860
documentation updated
Remove "bad nsa structure" error message
Chart : Transfert some logic from serveur to client #2853

Transfert some logic like chart basic structure and line styles. Only returns series now.
Correct a bug and optimise display on panel for ignored and overriden values (√, X or ! icons) and their respective value
Correct unit tests #2853

Remove one test that check the full chart structure (there is no more chart structure on server side)
Add button Show/Hide question labels on JMP-NSA view #2861
Reload exact tab in chart panel #2848
Add youtube embed sample
Partially revert 8e8da92 to go back to behavior of d578ed

We never inject series into chart implicitly. Only filters selected by
end-user are displayed on chart. This guarantuee maximum flexibility
and coherence with ignored elements.

Also all filters are always returned, because we cannot know what filter
may have been influenced by the projection.
Move test data into its own folder
Always refresh the filter displayed on chart
Hide alternative series if data are identical to original series #2848
Use filter color for adjusted series, because we may have several adjusted series by chart
Use dash styles that are as little confusing as possible
Minor variable renaming
Project only visible serie on chart

This force end-users to consciously select what he want to see
on chart, before starting a projection