Add normal computation for polygons
Docs: update faq, earthfiles
Update earthfiles.rst
Update faq.rst
PixelAutoTransform: add the missing default settings!
Add TerrainOptions::firstLOD property
Remove unimplemented method in TerrainOptions
Change ImageLayer::noDataImageFilename to be a URI; fix #269
Remove deprecated ObjectPlacer, fix cmake error
Merge pull request #273 from Oslandia/master

Normal computation
Add normals to polys in geometry filter; stub PMA in MP engine
DOC update (earth file ref), remove TerrainOptions::combineLayers (unused), change default earth file version to 2.
Registry: change default terrain engine => mp.
Add color filter ref guide stub
Update earthfile.rst
Update earthfile.rst
Update earthfile.rst
Update earthfile.rst
Update earthfiles.rst
Update earthfiles.rst