This fixes#552, reported by Rüdiger and Ayrat.
* tests/sanity/style.test: Warn aginst iterations on edge_vector.
* spot/parseaut/parseaut.yy, spot/twaalgos/complete.cc,
spot/twaalgos/parity.cc: Iterate over edges(), not edge_vector().
* tests/core/ltlcross.test: Add a test case for #552.
* NEWS: Mention the bug.
Fixes#546 (again).
* spot/twaalgos/gfguarantee.cc (g_f_terminal_inplace): Detect
true/false languages early, so that we do not tag them as
non-inherently-weak.
* tests/core/ltlcross.test: Improve test case.
Fixes#524, reported by Rüdiger Ehlers.
* spot/twaalgos/dbranch.cc: When merging an edge going to state
without successors simply delete it.
* bin/spot-x.cc: Typo in documentation.
* tests/core/ltlcross.test: Add a test case.
* NEWS: Mention the bug.
Reported by Salomon Sickert.
* spot/twaalgos/complement.cc: Make sure the output of postproc
is deterministic.
* tests/core/ltlcross.test: Add test case.
* NEWS: Mention the bug.
