Time values now populated up to the view layer
ECOMAPS-31 and 32

Multiple datasets can be rendered in the map at once, also the layers can be dragged into order
Added function to let users turn off individual legend graphics
ECOMAPS-38: Functionality to enable the user to select a time slice of a 3D dataset.

CSV file produced by python is ready to be used in the R code.
Merge branch 'master' of https://github.com/NERC-CEH/ecomaps