Global conversion to using floating point <--> string  functions insensitive to LC_NUMERIC (#5731)

git-svn-id: https://svn.osgeo.org/gdal/trunk@27942 f0d54148-0727-0410-94bb-9a71ac55c965
Fix windows compilation

git-svn-id: https://svn.osgeo.org/gdal/trunk@27943 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into trunk_travis_macosx