[CVS ci] event handling-1: some opcodes

[Leopold Toetsch]

The plan is to follow Gregors idea to swap op_func_table/op_addr array, 
if events got enqueued.
The internal check_events__ will get filled into a second op_func_table 
which will then take over.

There are still some questions:
- How does the actual event structure look like?
- Is this a QUEUE_ENTRY?
- And when yes, how to construct an entry in a sig_handler? -
  Malloc seems to be dangerous there.
leo