Remove sscanf() use in gdaltransformer, and remove CPLLocaleC enforcers in open, create, createcopy of drivers (#5731)

git-svn-id: https://svn.osgeo.org/gdal/trunk@27951 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into trunk_vc12