Added a main program called TableWrite. This program will write
out the photo-ionization and heating tables to unformatted files.
They can then be re-used or inspected.
The Makefile supports the building of TableWrite
Major work on the radiation module. Partly formatting, partly rewriting.
Changes include
- the capability for sources to be a sum of BB and PL spectra
- a limiting of the frequency bins used by the BB table searches
- much more ...
Added statement to produce output at the start of the simulation.
Updates the material and sourceprops modules for the test problem.

Synchronized with the H-only C2Ray_3Dm code.

Added temperature to the material module.

Added using a file with a list of source to the sourceprops module
Changed to the ifort compiler (was gfortran)

Modified to be able to build the test program C2Ray_3D_test_periodic
(and family)
Fixed bug: 1D output ("stream 1") was always accessing the temperature
array, even when the run was isothermal. This would give a seg fault
as the array would not be allocated in the isothermal case.
Factorized out the calculation of luminosity from mass of the halos.

This allows us to easier experiment with different recipes.
Fixed several bugs

1. The thread number was not initialized which leads to wrong behaviour
   when running with OpenMP. Now initialized to 1. See also history
   of evolve8.F90 in C2Ray_3Dm

2. When checking for convergence the test was <= to the criterion.
   For few sources the criterion is the number of sources. For weak
   sources the number of cells changes will be equal to the number
   of sources. The code would decide "converged" before the sources
   get a chance to help each other. Changed to < the criterion.
Example of the standard set of sources for the test problem.
Updated in order to be able to run the test problem:
100 Mpc box with 10 sources.
Some editing of the standard source parameters section.
Added a comment about a statement which appears to be superfluous
Added making of TableWrite to the Makefile.

TableWrite does belong in this directory. This should be fixed!
Moved TableWrite.F90 to the files_for_1D directory.