v2.0: Dynamic Force fully defined in python interface for sol 312, 912

Fortran:
- interface updated to receive full dynamic force in input (ForceDynamic) but also the old variables (ForceTime,ForceDynAmp) that are used with the other dynamic solutions
- opt_fd_prealloc eliminated from makefile and from main fortran program

Python:
- other solution work only with old way to define force (modal)
- load package created. 
- module load.modal (ex module load) contains all method for old dynamic force definition
- xbcomponent updated

Other:
- small bug fix in lib.integr, lib.postpr