CSV: add QUOTED_FIELDS_AS_STRING open option that default to NO. So by default, if AUTODETECT_TYPE=YES, the content of quoted fields will be tested for real, integer,... data types

git-svn-id: https://svn.osgeo.org/gdal/trunk@27829 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into trunk_vc12