TODO

FEATURES
 - Ensure inv_inhom_effective_size used for fractal entrapment
 - Option to have more McICA columns to reduce noise
 - Incorporate UV processor

LONGER TERM FEATURES
 - Option to provide date, time, longitude and latitude from which the
   IFS values will be calculated of: solar zenith angle, trace gas and
   aerosol mixing ratio, and cloud effective ratio
 - Complete surface radiative transfer component including vegetation
   and urban surfaces (?)
 - Incorporate RRTMGP and FSCK

INTERFACE
 - Rename "do_3d" as it is misleading
 - Add deallocate method for config type
 - Column is last array argument for all input and output arrays?
 - Why are the flux%*_band variables dimensioned (g,col,lev) not (g,lev,col)?

DOCUMENTATION
 - Add chapters on API, internal structure and underpinning science

MISC
 - Definition of Tdir in two_stream

DIFFERENCES IN IFS VERSION OF ECRAD
 - Numerous files contain easy_netcdf_with_read_mpi instead of easy_netcdf
 - radiation_cloud_generator.F90 contains SIMD routine
 - radiation_delta_eddington.h contains SIMD routine
 - radiation_mcica_*.F90 contain Intel optimizations
 - radiation_interface.F90 and radiation_ifs_rrtm.F90 take YDERAD arguments

KNOWN BUGS