Fix issues in construction module

docs/Lua API.rst

@@ -1912,7 +1912,8 @@ Constructions module
 
 * ``dfhack.constructions.insert(construction)``
 
-  Properly inserts the given construction into the game.
+  Properly inserts the given construction into the game. Returns false and fails to
+  insert if there was already a construction at the position.
 
 Kitchen module
 --------------

library/LuaApi.cpp

@@ -2264,6 +2264,7 @@ static const luaL_Reg dfhack_buildings_funcs[] = {
 
 static const LuaWrapper::FunctionReg dfhack_constructions_module[] = {
     WRAPM(Constructions, designateNew),
+    WRAPM(Constructions, insert),
     { NULL, NULL }
 };
 
@@ -2286,7 +2287,6 @@ static int constructions_findAtTile(lua_State *L)
 static const luaL_Reg dfhack_constructions_funcs[] = {
     { "designateRemove", constructions_designateRemove },
     { "findAtTile", constructions_findAtTile },
-    WRAPM(Constructions, insert),
     { NULL, NULL }
 };
 

library/include/modules/Constructions.h

@@ -45,6 +45,8 @@ namespace Constructions
 
 DFHACK_EXPORT df::construction * findAtTile(df::coord pos);
 
+DFHACK_EXPORT bool insert(df::construction * constr);
+
 DFHACK_EXPORT bool designateNew(df::coord pos, df::construction_type type,
                                 df::item_type item = df::item_type::NONE, int mat_index = -1);