"Strategy" was used for mealy machines and game strategies a like.
Introduced the notion of mealy machine in three different flavors:
mealy machine: twa_graph with synthesis-outputs
separated mealy machine: mealy machine and all transitions
have conditions of the form (bdd over inputs)&(bdd over outputs)
split mealy machine: mealy machine that alternates between
env and player states. Needs state-players

* bin/ltlsynt.cc: renaming
* python/spot/impl.i: Add vector for const_twa_graph_ptr
* spot/twaalgos/aiger.cc,
spot/twaalgos/aiger.hh: Adapting functions
* spot/twaalgos/mealy_machine.cc,
spot/twaalgos/mealy_machine.hh: Add test functions and
propagate properties correctly. Adjust for names
* spot/twaalgos/synthesis.cc,
spot/twaalgos/synthesis.hh: Removing unnecessary functions
and adapt to new names
* tests/python/aiger.py,
tests/python/_mealy.ipynb,
tests/python/mealy.py,
tests/python/synthesis.ipynb: Adjust