* src/twa/acc.cc: Allow duplicate and reordered pairs.  Also recognize
the single-pair cases.
* src/twaalgos/hoa.cc: When Rabin or Streett is detected, canonicalize
the Acceptance: line.
* src/tests/hoaparse.test, wrap/python/tests/accparse2.py: More tests.
* src/tests/sbacc.test: Adjust.