* arts-2-1-718

* controlfiles/artscomponents/tmatrix/TestTMatrixSSD.arts:

Adapted testcase to use scat_data_meta_array.

* src/m_physics.cc: Added ParticleRefractiveIndexConstant.

* src/workspace.cc: Updated docs for scat_data_meta_array.

* src/tmatrix.{cc,h} (calcSingleScatteringDataProperties):

Removed phase.

* src/methods.cc: Added SingleScatteringData to Extract.

Added ParticleRefractiveIndexConstant, scat_data_meta_arrayInit.

Renamed single_scattering_dataCalcTMatrixTest to
scat_data_rawFromTMatrix.

* src/m_tmatrix.cc:

(scat_data_meta_arrayAdd): Made it compatible with cylinders and 
spherical particles with other aspect ratios than one. removed 
density as an input, which is now set using the input material. 
Added the feature to autocreate a descriptoin based on the input data.

(scat_data_rawFromTMatrix):  Made it compatible with cylinders and 
spherical particles with other aspect ratios than one.


git-svn-id: https://www.sat.ltu.se/svn/rt/arts/trunk@8569 aaf1aab0-4228-0410-ad68-8dceda47f409