Add NCF-213 to release notes

git-svn-id: https://sub.unidata.ucar.edu/netcdf/trunk@3125 2e3060e4-1ed8-cf1f-9cc2-9586e844a556
Revert nc4file.c to r3113, because r3123 version broke --enable-extra-tests build

git-svn-id: https://sub.unidata.ucar.edu/netcdf/trunk@3126 2e3060e4-1ed8-cf1f-9cc2-9586e844a556