Allow direct input of AV data

[stefanfluck]

currently, AV data needs to be split by category as pavementareas and bb shapefiles. This can be simplified. idea: Download Amtliche Vermessungsdaten as shapefile in Format DM.01-AV-CH (or -ZH etc), and provide list which categories belong to which. Include variable that says which datastandard AV data are in (e.g dm01avch or dm01avzh, containing list bbcats = 5,10,etc and pavcats = 19,40,39 etc).

[stefanfluck]

still a good idea

test if implementation of "surf_data_mode" works as expected (in code it says "not tested yet", but I surely tested it...)