* spot/misc/satsolver.hh: Make solver return vector<bool> instead of
vector<int>.
* spot/misc/satsolver.cc: Update code.
* spot/priv/Makefile.am: Add satcommon.*
* spot/priv/satcommon.hh: Declare helper class and factorize some
duplicate code of dt*asat.cc
* spot/priv/satcommon.cc: Implement helper class and factorize some
duplicate code of dt*asat.cc
* spot/twaalgos/dtbasat.cc: Declare helper, implement some functions
in dict struct and update code.
* spot/twaalgos/dtwasat.cc: Declare helper, implement some functions
in dict struct and update code.
* tests/core/readsat.cc: Update tests.
* tests/core/satmin.test: Typo.
* tests/core/satmin2.test: Update an expected result.