Let win/dialog.c and win/menubar.c define input_modal_string,
input_modal_number, menu_open and menu_init directly instead of
dispatching to them through wrappers.
Linux and macOS now both build the pure-SDL + microui menu. Remove GTK3
detection, the ENABLE_GTK build branches, and the GTK menu sources.
Decouple gettext NLS from ENABLE_GTK so menu labels stay translatable on all
desktop builds, and update i18n to the new sources (POTFILES.in, .pot, ja.po).
Vendor microui 2.02 under src/microui/ and use it to draw an in-game
popup menu as an overlay.
modal.c provides generic modal infrastructure: a loop that pumps SDL
events into microui and renders the command list via SDL_Renderer,
hooked into gfx_updateScreen(). menu_sdl.c builds the concrete popup
menu on top of it.
gtk_menu_popup() is deprecated since GTK 3.22. Since no GdkEvent is
available at the call site, use gtk_menu_popup_at_rect() with the
current pointer position obtained via gdk_device_get_position().
kichikuou