remove X11 GUI

CMakeLists.txt

src/aevol_create.cpp

src/aevol_propagate.cpp

src/aevol_run.cpp

src/change_env.cpp

src/change_exp_setup.cpp

src/change_pop.cpp

src/libaevol/CMakeLists.txt

src/libaevol/aevol.h

src/libaevol/gui/X11Window.cpp

src/libaevol/gui/X11Window.h

src/libaevol/legacy/ExpManager.cpp

src/libaevol/legacy/ExpManager_X11.cpp

src/libaevol/legacy/ExpManager_X11.h

src/libaevol/legacy/population/Individual.cpp

src/libaevol/legacy/population/IndividualFactory.h

src/libaevol/legacy/population/Individual_X11.cpp

src/libaevol/legacy/population/Individual_X11.h

src/libaevol/legacy/raevol/Individual_R_X11.cpp

src/libaevol/legacy/raevol/Individual_R_X11.h