* arts-2-1-485

* src/xml_io_array_types.cc, src/xml_io_compound_types.cc,
src/xml_io_instantiation.h, src/xml_io_types.h:

Implement XML reading/writing of CIARecord and ArrayOfCIARecord.

* src/methods.cc, src/m_cia.cc:

Add abs_cia_dataReadFromXML. Reads CIA data from XML file and
checks
that all CIA species from abs_species are defined in that file.

* src/cia.h (CIARecord):

Change runtime errors to assertions in getters.

Add getter for const reference to mdata.

Be friend with xml_read_from_stream.

git-svn-id: https://www.sat.ltu.se/svn/rt/arts/trunk@8168 aaf1aab0-4228-0410-ad68-8dceda47f409