Automata (SABA).
* src/saba/saba.hh, src/saba/saba.cc, src/saba/sabastate.hh,
src/saba/sabasucciter.hh: New. Interface for
SABA (State-labeled Alternating Büchi Automata).
* src/saba/explicitstateconjunction.cc,
src/saba/explicitstateconjunction.hh: New. Default
implementation for a conjunction of states.
* src/saba/Makefile.am: New.
* src/Makefile.am, configure.ac: Adjust.
* src/sabaalgos/sabareachiter.cc,
src/sabaalgos/sabareachiter.hh: New. Iterate over all reachable
states of a spot::saba.
* src/sabaalgos/sabadotty.cc, src/sabaalgos/sabadotty.hh: New.
Print reachable states in dot format.
* src/sabaalgos/Makefile.am: New.
