Make all python code compatible with Python 2.x and Python 3.x.
* wrap/python/buddy.i (__le__, __lt__, __eq__, __ne__, __ge__ __gt__): New operators for bdd. * wrap/python/spot.i (__le__, __lt__, __eq__, __ne__, __ge__ __gt__, __hash__): New operators for formula. (nl_cout, nl_cerr): New functions. * wrap/python/tests/bddnqueen.py, wrap/python/tests/interdep.py, wrap/python/tests/ltl2tgba.py, wrap/python/tests/ltlparse.py, wrap/python/tests/ltlsimple.py, wrap/python/tests/minato.py, wrap/python/tests/modgray.py: Adjust to the new print syntax by using sys.output.write() or nl_cout() instead. * wrap/python/tests/optionmap.py: Remove all print calls. * wrap/python/ajax/spot.in: Massive adjustments in order to work with both Python 2 and 3. In python 3, reopening stdout as unbuffered requires it to be open as binary, which in turns requires any string output to be encoded manually. BaseHTTPServer and CGIHTTPServer have been merged into http.server, so we have to try two different import syntaxes. execfile no longer exists, so it has to be emulated. This also fixes two bugs where the script would segfault on empty input, or when calling Tau03 on automata with less then one acceptance conditions.