Rationalize PYACC.Text so it occurs only once inside containers like PYACC.Char,...

Rationalize PYACC.Text so it occurs only once inside containers like PYACC.Char, and so that embedded references like PYACC.Escape now become PYACC.Text.Escape and occur inside PYACC.Text instead of being interspersed with PYACC.Text nodes