Filter out bus stops which have to type defined
Rename tramStopType => unknownType
Merge pull request #234 from finnishtransportagency/filter-unknown-bus-types-for-vallu

Filter out bus stops which have to type defined
Exclude tram and unknown stop types from xml export to Vallu.
Fetch road links using backend utils
Remove redundant object wrapper
Draw road links on map
Remove road links when zooming out
Implement stub function for determining road link style
Transform road links in backend utils
Merge pull request #235 from finnishtransportagency/filter-tram-and-unknown-stops-from-vallu-xml

Exclude tram and unknown stop types from xml export to Vallu.
Merge from master