Function push_margin

plugins/siege-engine.cpp:1286–1292

std::map<df::unit*, UnitPath*> UnitPath::cache;

static void push_margin(lua_State *L, float margin)
{
    if (margin == MAX_TIME)
        lua_pushnil(L);
    else
        lua_pushnumber(L, margin);
}

static int traceUnitPath(lua_State *L)
{