Dataset title, better filter display & download modal

[jameshadfield]

This PR introduces

• a title ("info") card above the map/tree, which contains the dataset title and a list of active filters (see screenshots). This card is collapsable via a toggle.
• an expanded footer to contain all available filters (see screenshots)
• the removal of filters from the sidebar
• the download modal is now running.

Blocking:

• The data attribution needs to be written - @trvrb - Data attribution needs to be written #431

Notes:

• This is live and working for zika at http://auspice-dev.herokuapp.com/zika
• Augur should be rerun for most datasets - this is happening this week. After this, the controls can be removed from the metadata JSON, but this can be left in for now.
• This still works relatively gracefully on "older" augur builds - see http://auspice-dev.herokuapp.com/flu, http://auspice-dev.herokuapp.com/dengue
• Bugs map SVG is broken after panning - panes are blank #429 and Map SVG demes & transmissions need translating #450 remain and will be fixed eventually.
• closes Display author and title when filtering by author #354

Screenshots

[jameshadfield]

@trvrb I think this is ready to be merged now

[trvrb]

Thanks @jameshadfield. There were a couple small bits of logic that I was wanting to adjust. I'll do this now and then we can merge if you're happy with them.

[trvrb]

@jameshadfield --- I just removed date filters from the info box. I didn't like how the numbers flipped through while dragging date slider. I you feel strongly I'm happy to discuss / undo.

I also disable the data download button so that this can be merged now and not depend on #431 (I'll do this, I promise).

We still need new JSONs for flu, H7N9 and Ebola, but this can happen before pushing live (and it's not terrible without the new JSONs).

Going to merge now.