update:
small updated to this reshuffled version.
Compilation had some problems, now fixed.

code updated and reshaped following integration with ED code.

The new structure is:
- the solvers are contained in specific directory named <SOLVER>_SOLVER
- the INPUT_VARIABLES used in the specfic solver are merged into the module contained
in the main RDMFT directory: SOLVER_INPUT_VARS, this ensure that each solver has its own input variables
and there no multiple copies of them.
- the Makefile in each SOLVER directory has to be tweaked to compile (if necessary) first the SOLVER_INPUT_VARS in the
main dir, compile the solver code into a library.
- the Makefile of RDMFT make use of the above mentioned library and modules from all solvers.
- the solver are USED (in the f90 sense) in the RDMFT module.

Code to be tested: ED Vs. IPT, homo Vs. inhomo.
updated structure of the code to fit the introduction of PARSE_INPUT in SciFor.

The input variables from RDMFT and all solver are merged into RDMFT_INPUT_VARS module.

The interface to the specific solver is contained into a wrapping module, e.g. RDMFT_WRAP_IPT,
which in turn call the proper modules to enable use of the solver, e.g. DMFT_IPT.

All the auxiliary functions are store into RDMFT_AUX_FUNX.