Updated CS identity from CS Systèmes d'Information to CS GROUP

src/main/java/org/orekit/rugged/raster/TileFactory.java

src/main/java/org/orekit/rugged/raster/TileUpdater.java

src/main/java/org/orekit/rugged/raster/TilesCache.java

src/main/java/org/orekit/rugged/raster/UpdatableTile.java

...t/rugged/refraction/AtmosphericComputationParameters.java

...a/org/orekit/rugged/refraction/AtmosphericRefraction.java

...org/orekit/rugged/refraction/ConstantRefractionLayer.java

...in/java/org/orekit/rugged/refraction/MultiLayerModel.java

src/main/java/org/orekit/rugged/utils/DSGenerator.java

src/main/java/org/orekit/rugged/utils/ExtendedEllipsoid.java

src/main/java/org/orekit/rugged/utils/GridCreation.java

src/main/java/org/orekit/rugged/utils/MaxSelector.java

src/main/java/org/orekit/rugged/utils/MinSelector.java

...java/org/orekit/rugged/utils/NormalizedGeodeticPoint.java

...ava/org/orekit/rugged/utils/RoughVisibilityEstimator.java

src/main/java/org/orekit/rugged/utils/Selector.java

...ava/org/orekit/rugged/utils/SpacecraftToObservedBody.java

src/site/markdown/building.md

src/site/markdown/configuration.md

src/site/markdown/contact.md