Vendor the Shockolate engine and build it via a Docker image with every

dependency (SDL2, SDL2_mixer, fluidsynth-lite, a MIDI soundfont)
prebuilt, so compiling the engine needs no network access - just the
image and the engine source. Add res/assets/extract_assets.sh to pull
the game's data files out of a purchased GOG installer, and a Makefile
that assembles a runnable dist/ from the two.

Also add `make package`, which builds a redistributable tarball that
omits the proprietary game assets (shipping res/GET_ASSETS.txt instead)
plus license information for both the MIT tooling and the GPLv3 engine,
and a Gitea Actions workflow that builds and publishes it to
dl.ladkau.de on every push.

engine/src/GameSrc/Headers/invent.h

@@ -0,0 +1,105 @@
+/*
+
+Copyright (C) 2015-2018 Night Dive Studios, LLC.
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+#ifndef __INVENT_H
+#define __INVENT_H
+
+/*
+ * $Source: r:/prj/cit/src/inc/RCS/invent.h $
+ * $Revision: 1.14 $
+ * $Author: xemu $
+ * $Date: 1994/07/18 21:31:31 $
+ *
+ */
+
+// Includes
+#include "invdims.h"
+
+// C Library Includes
+
+// System Library Includes
+#include "objects.h"
+
+// Master Game Includes
+
+// Game Library Includes
+
+// Game Object Includes
+
+#define MAX_GENERAL_INVENTORY 12
+
+// Prototypes
+
+// creates and initializes the inventory region
+LGRegion *create_invent_region(LGRegion *parent, LGRegion **pbuttons, LGRegion **pinvent);
+
+// Draw the inventory area.  Keeps information on most recent draw so only does
+// incremental updates.
+errtype inventory_draw(void);
+
+// Force the inventory panel to draw, no matter what
+errtype inventory_full_redraw(void);
+
+// switch the inventory page to pgnum and redraw
+errtype inventory_draw_new_page(int pgnum);
+
+// clears the inventory region
+errtype inventory_clear(void);
+
+// Add the appropriate kind of object to the player's inventory.   Returns whether
+// or not the action succeded (typical failure reason being not enough inventory
+// slots remaining).
+uchar inventory_add_object(ObjID new_object, uchar select);
+
+// Removes the specified object from the player's inventory.  Does not do any
+// correlation with the rest of the Universe -- this needs to be handed by
+// the dropping/consuming/destroying code.
+errtype inventory_remove_object(ObjID new_object);
+
+void draw_page_buttons(uchar full);
+
+void inv_change_fullscreen(uchar on);
+void inv_update_fullscreen(uchar full);
+
+errtype inventory_update_screen_mode();
+
+void push_inventory_cursors(LGCursor *newcurs);
+void pop_inventory_cursors(void);
+
+void super_drop_func(int dispnum, int row);
+void super_use_func(int dispnum, int row);
+
+void absorb_object_on_cursor(ushort keycode, uint32_t context, intptr_t data);
+
+uchar cycle_weapons_func(ushort keycode, uint32_t context, intptr_t data);
+
+void push_live_grenade_cursor(ObjID obj);
+
+void set_current_active(int activenum);
+
+void remove_general_item(ObjID obj);
+
+void add_email_datamunge(short mung, uchar select);
+
+void invent_language_change(void);
+
+// Globals
+extern short inventory_page;
+extern short inv_last_page;
+
+#endif // __INVENT_H