Boolector 3.1.0

Changes:

• build system:
  • requires now cmake >= 3.3
  • exports library interface for using find_package(Boolector) in cmake projects
• support for custom abort callback function
  (called on abort instead of actually aborting)
• Python API now throws Python exceptions on abort conditions
  (e.g., when underlying C API is misused)
• command line options that previously expected integer values denoting enum
  values are now configured with strings denoting the particular modes that
  can be selected; -=help and --=help allow to print detailed help
  messages for these modes
• fixed issue in SMT2 parser to correctly print echo commands
  (thanks to Dominik Klumpp)
• fixed race condition in Cython dependencies
  (thanks to Marco Gario)
• patches and documentation for building Boolector on Windows
  (thanks to Andrew V. Jones)
• support/use termination function feature of CaDiCaL
  (thanks to Andrew V. Jones)
• various fixes to contrib dependecy scripts
  (thanks to Serge Bazanski)
• new API calls
  • boolector_copy_sort
  • boolector_min_signed
  • boolector_max_signed
  • boolector_is_bv_const_zero
  • boolector_is_bv_const_one
  • boolector_is_bv_const_ones
  • boolector_is_bv_const_min_signed
  • boolector_is_bv_const_max_signed
• CaDiCaL is now default SAT engine
• support for constant arrays
• support for GMP as bit-vector implementation
• support for CyproMiniSat
  • supports multi-threading via option --sat-engine-n-threads
• switched to Google test as testing framework
• CLI options changed (replaced ':' with a '-')
• BtorMC improvements (HWMCC'19 version)
  • k-induction engine with simple path constraints
• Poolector Python script used in SMT-COMP'19