This library, called libspotgen, gathers functions to generate classes
of automata found in the literature.
Related to #254.
* NEWS, README: Mention the modification.
* Makefile.am, debian/control, debian/libspotgen0.install: Build the new
library in a separate package.
* spot/gen/automata.hh, spot/gen/automata.cc: Add a family of co-Büchi
automata.
* configure.ac, spot/Makefile.am, spot/gen/Makefile.am: Build the new
library.
