Get information for a map type

The function prints the information used in internal calculations by the basemap function

map_type(type)

Arguments

type	A character argument giving the type of map area. See `type` in `basemap`.

Returns a list of different map type definitions required by the basemap function. The list consists of following elements:

land name of the land shapefile.
glacier name of the glacier shapefile. NULL if glaciers are not provided.
boundary either a shapefile or a limit argument defining the default limits for the map. Will be overriden by the basemap limit argument.
map.type defines the class of the map with "svalbard", "barents", and "panarctic" as options. Due to more and longsighted naming early on during the package writing, this argument got the name map.type, which is unfortunate. Should be changed to map.class eventually.
round.lon,round.lat default rounding arguments specifying the level of rounding to be used to plot longitude and latitude grid lines.