- example: noj_terrain_following.py
- move all distance calculation to distance.py
- old TerrainFollowingDistance function(from Movflot) renamed to TerrainFollowingDistance2
- new simpler and more efficient TerrainFollowingDistance implemented
- WaspGridSite renamed to WaspGridSiteBase.
- New backward-compatible WaspGridSite that allows different Distance calculation objects
- tests

deleted test_examples.py as all example modules are tested in test_main.py

- ti_map added
- default ti changed from 0.75 to 0.075

Merge branch 'update_uniform' of https://gitlab.windenergy.dtu.dk/TOPFARM/PyWake into update_uniform