* arts-2-1-886

* src/methods.cc, src/m_nc.h (WriteNetCDFIndex):

Added writing of indexed NetCDF files analogous to WriteXMLIndexed.

git-svn-id: https://www.sat.ltu.se/svn/rt/arts/trunk@8871 aaf1aab0-4228-0410-ad68-8dceda47f409