Kill children in ~TuringState() by calling erase(true)
Update README.md

TODO += Add state-IDs.
Implemented TuringState-IDs
Use TURING_POINTER instead of TURING_STATE (char) in erase()
Kind of verbosity in erase_state()
Fixed typo
Implemented debug_cmd "clone [id]" and "add".
Give TuringMashine::eraseState() a zero-based parameter.