Update rendering_types; add ncn/lcn,nwn/lwn

Next to regional walking (rwn_ref) and cycling (rcn_ref) nodes, also add national (nwn/ncn) and local (lwn/lcn) network nodes
Update rendering_types.xml

Also add international walking (iwn) and cycling (icn) network nodes
Merge pull request #209 from hvdwolf/master

Add international, national and local network nodes to cycle/walking networks