GetSpatialRef is not available with gdal2, so we need
to use GetProjectionRef

Merge branch '2221_clean_of_elevation_parameters' of https://gitlab.orfeo-toolbox.org/orfeotoolbox/otb into 2221_clean_of_elevation_parameters

They were removed by mistake.

REFAC: add warning messages when geoid or dem cannot be opened and don't try to use a null dataset to create the shifted dataset when the geoid cannot be opened

REFAC: make ClearDEMs private in otb::DEMHandler to force the usage of the new API (ClearElevationParameters) in OTB 8.0

REFAC: add a DEMHandler::CleanElevationParameters method that clear DEMs, geoid and defaut height above ellipsoid

REFAC: add warning messages when geoid or dem cannot be opened and don't try to use a null dataset to create the shifted dataset when the geoid cannot be opened

Don't search and package boost date time

See merge request !880

REFAC: make ClearDEMs private in otb::DEMHandler to force the usage of the new API (ClearElevationParameters) in OTB 8.0

REFAC: add a DEMHandler::CleanElevationParameters method that clear DEMs, geoid and defaut height above ellipsoid

Update CI to use the latest centos7 version

See merge request !875

Fix segfault in Monteverdi

Closes #2241

See merge request !874

BUG: fix ImageMetadata pointer checks in GlImageActor and use OutputImageMetadata in m_ImageToViewportTransform in Ice::GlImageActor

Implement a GetSize() function for the ImageMetadata class

Closes #2237

See merge request !872

Update geospatial libraries versions in Superbuild (WIP)

See merge request !865

WorldToEcef and EcefToWorld free functions

See merge request orfeotoolbox/otb!873

Merge remote-tracking branch 'origin/sb_update_geospatial_lib_versions' into sb_update_geospatial_lib_versions

BUG: add GCP to SPOT5_ROI_1000_100.tif as gcp are now correctly read in the apTvRaOpticalCalibration_Spot5 baseline (fix in the HFA driver)

BUG: update optical calibration input images to take into account GDAL bug 4591 (GCP were not read correctly in img files and these images are tif conversion of img files)