Function 'maps.flights' source, originally from 'commuting_flight_comparisons_maps.R'
Script can be sourced for use in other scripts.
Define flights to map, added possibility to specify which flights to plot, provide a vector of flight_id, can be a unit vector. Default is 'FALSE'.
Prority:
all.flights > flight.id > flight.num
database function and mapping
Completed testing of function - now to write version to run for all flights