Get rid of invoke_engio

luprex/cpp/core/invocation.hpp

@@ -12,13 +12,11 @@
 //
 //   Nothing.
 //
-// KIND_ENGIO:
+// KIND_LUA_CALL:
+//
+//   A lua function call.  The class name, the function name, and then
+//   the function arguments.
 //
-//   First, a function name is read from the datapack.  The function
-//   name must be a lua function inside class "engio".  The function
-//   is called with arguments: actor, place, and then additional
-//   arguments of simple dynamic type read from the datapack.
-// 
 // KIND_LUA:
 //
 //   A block of lua source code, in plaintext.
@@ -50,7 +48,6 @@ class Invocation : public eng::opnew {
 public:
     enum Kind {
         KIND_INVALID,
-        KIND_ENGIO,
         KIND_LUA_CALL,
         KIND_LUA,
         KIND_FLUSH_PRINTS,