Update vehicle profiles to take incline tags into account

[Sébastien Ouellet]

It's possible for field workers to identify roads too steep to be traversed, so we should have versions of our vehicle profiles that avoid anything with

1. incline=up or down
2. incline=15% and more/ -15% and less

Then it's up to the users to edit the road section on OSM with the right tag.

[Sébastien Ouellet]

incline=steep is the key:value tag we'll use for simplicity, the profile is named avoidsteep3wheeler.lua