code: function ConfigStack(){
    this._stack = new Uint32Array( ( (LEN|0) * MIN_ALLOC)|0 );
    this._sets  = new Uint32Array( MIN_ALLOC|0 );
    this._tmpDat = new Uint32Array( LEN|0 );
    this._size  = MIN_ALLOC|0;
    this._ptr   = 0;
  
    this._headPos = 0;
    this._wcfg = new GLConfig();
  }
docs: A, B, C, D, E, F, ?   -- initial config 1, 1, 1, 1, 1, 1, 0  ?, ?, X, D, ?, ?, ?   -- push config 0, 0, 1, 1, 0, 0, 0   -- cfg set 1, 1, 1, 1, 1, 1, 0   -- new set 0, 0, 0, 1, 0, 0, 0   -- diffs