* src/tgbaalgos/dotty.cc: Specialize for tgba_digraph_ptr.
* src/tgba/tgbagraph.hh, src/tgbaalgos/dupexp.cc: Copy properties by
default when cloning an automaton.
* src/tgbatest/det.test, src/tgbatest/dstar.test,
src/tgbatest/ltl2tgba.test, src/tgbatest/monitor.test,
src/tgbatest/neverclaimread.test, src/tgbatest/tgbaread.test: Adjust
tests.