Simple Network field in Road Route relation preset

Ref #2369
Update imagery
Pin maki version
Merge pull request #2372 from 1ec5/road-network

Simple Network field in Road Route relation preset
Update translations
1.6.0
Suppress tail in walkthrough (fixes #2362)
fix for the failures under safari/webkit
support zoom in/out with shifted or unshifted keys +,-,=,_
also add new Firefox-specific keycodes to `d3.keybinding.js`
closes #2389
remove smoking field for camp_site preset (closes #2390)
Better support for amenity=bus_station (closes #2308)
add amenity=community_centre preset (closes #2243)
Fix performance regressions in tree.js (fixes #2396)
Add mutating extent extend, for performance
Optimize Way#area
Fix build
Fix build
Eliminate floating point error in zoomIn/zoomOut
(closes #2394)
Fix the link in CONTRIBUTING.md for searching existing issues (currently uses a user's repo rather than the OSM org)
Merge pull request #2405 from daguar/fix-link-for-searching-issues-in-contributing-md

Fix the link in CONTRIBUTING.md for searching existing issues