#TODO: help_string & usage_string:

gui/about.cpp
gui/browser.cpp
gui/chooser.cpp
gui/downloaddialog.cpp
gui/editgamedialog.cpp
gui/editrecorddialog.cpp
gui/filebrowser-dialog.cpp
gui/fluidsynth-dialog.cpp
gui/gui-manager.cpp
gui/KeysDialog.cpp
gui/KeysDialog.h
gui/launcher.cpp
gui/massadd.cpp
gui/onscreendialog.cpp
gui/options.cpp
gui/predictivedialog.cpp
gui/recorderdialog.cpp
gui/remotebrowser.cpp
gui/saveload-dialog.cpp
gui/themebrowser.cpp
gui/ThemeEngine.cpp
gui/unknown-game-dialog.cpp
gui/updates-dialog.cpp
gui/widget.cpp

base/main.cpp

common/error.cpp
common/rendermode.cpp
common/updates.cpp

engines/advancedDetector.cpp
engines/dialogs.cpp
engines/engine.cpp
engines/game.cpp

audio/mididrv.cpp

backends/cloud/cloudmanager.cpp
backends/cloud/storage.cpp
backends/dialogs/gtk/gtk-dialogs.cpp
backends/dialogs/macosx/macosx-dialogs.mm
backends/dialogs/win32/win32-dialogs.cpp
backends/events/default/default-events.cpp
backends/graphics/surfacesdl/surfacesdl-graphics.cpp
backends/graphics/sdl/sdl-graphics.cpp
backends/keymapper/hardware-input.cpp
backends/keymapper/remap-widget.cpp
backends/keymapper/virtual-mouse.cpp
backends/networking/sdl_net/handlers/createdirectoryhandler.cpp
backends/networking/sdl_net/handlers/downloadfilehandler.cpp
backends/networking/sdl_net/handlers/filesajaxpagehandler.cpp
backends/networking/sdl_net/handlers/filespagehandler.cpp
backends/networking/sdl_net/handlers/indexpagehandler.cpp
backends/networking/sdl_net/handlers/uploadfilehandler.cpp
backends/networking/sdl_net/handlerutils.cpp
backends/networking/sdl_net/localwebserver.cpp
backends/networking/sdl_net/uploadfileclienthandler.cpp
backends/platform/sdl/macosx/appmenu_osx.mm
backends/updates/macosx/macosx-updates.mm