Fix CPLAtof()/CPLStrtod() to avoid parsing '2,34' as 2.34 in a locale with comma as decimal separator (#5731)

git-svn-id: https://svn.osgeo.org/gdal/trunk@27944 f0d54148-0727-0410-94bb-9a71ac55c965
Remove now useless manual replacing of comma by point in a few drivers (#5731)

git-svn-id: https://svn.osgeo.org/gdal/trunk@27945 f0d54148-0727-0410-94bb-9a71ac55c965