* src/main.c (main): When traces are enabled, display the Bison
version.
* tests/conflicts.at, tests/report.at, tests/sets.at:
Use AT_PACKAGE_VERSION (for package.m4) instead of post-processing the
output.
Reported by Hans Åberg.
https://lists.gnu.org/archive/html/help-bison/2019-02/msg00064.html
* src/files.c (spec_graph_file): Use `*.gv` when 3.4 or better,
otherwise `*.dot`.
* src/parse-gram.y (handle_require): Pretend we are already 3.4.
* doc/bison.texi: Adjust.
* tests/local.at, tests/output.at: Exercise this.