#1746 - Ebola Page: add cases choropleth to map
#1746 - implement changes requested by Javier
           - style changes on the layers popup
#1746 - fixed some layers not being highlighted on hover
#1746 - style medical centers dots
           - bring dots to front on hover
           - fix medical centers info with "null" apearing
#1691 - updating Simon's graph
#1746 - emphasise layer title
Merge branch 'dev' into arti-sprint-39
Merge pull request #1755 from OCHA-DAP/arti-sprint-39

Arti sprint 39