Mark osmium::geom::CRS and Projection classes as deprecated

Author: joto

include/osmium/geom/projection.hpp

@@ -68,7 +68,7 @@ namespace osmium {
          *
          * @deprecated Only supports the old PROJ API.
          */
-        class CRS {
+        class OSMIUM_DEPRECATED CRS {
 
             struct ProjCRSDeleter {
                 void operator()(void* crs) {
@@ -143,7 +143,7 @@ namespace osmium {
          *
          * @deprecated Only supports the old PROJ API.
          */
-        class Projection {
+        class OSMIUM_DEPRECATED Projection {
 
             int m_epsg;
             std::string m_proj_string;