modified:   code.py
- LinearCode added, that will be the DUMB code, when representer() will
  be with linear(!) search
- dump() and read() added to LinearCode
modified:   code.py
LinearCode.representer() added
modified:   code.py
- added factory method, other read() methods and __dump_header() as
  well
modified:   code.py
- some bugfixes and typos in LogLinCode