- Merge #523: fix: free() call more than once with the same pointer.

* nlnet/master: (37 commits)
  - Fix to print error from unbound-anchor for writing to the key   file, also when not verbose.
  - For NLnetLabs#519: fix comments for doxygen.
  - For NLnetLabs#519: yacc and lex. And fix python bindings, and test program   unbound-dnstap-socket.
  Changelog note for NLnetLabs#519 and example.conf edit - Merge NLnetLabs#519: Support for selective enabling tcp-upstream for   stub/forward zones. - For NLnetLabs#519: note stub-tcp-upstream and forward-tcp-upstream in   the example configuration file.
  Changelog note for NLnetLabs#523 - Merge NLnetLabs#523: fix: free() call more than once with the same pointer.
  Changelog note for NLnetLabs#521 - Merge NLnetLabs#521: Update mini_event.c.
  - Add test tool readzone to .gitignore.
  - And 1.13.2rc1 became the 1.13.2 with the fix for the python module   build. The current code repository continues with version 1.13.3.
  fix: free() call more than once with the same pointer
  Update mini_event.c
  - Fix NLnetLabs#520: Unbound 1.13.2rc1 fails to build python module.
  Add (stub|forward)-tcp-upstream options which enable using tcp transport only for specified stub/forward zones
  For 1.13.2rc1.
  - Tag for 1.13.2 release.
  - Fix unit test zonemd_reload for use in run_vm.
  - Fix libnettle zonemd unit test.
  - Fix out of sourcedir run of zonemd unit tests.
  - Fix readzone compile under debug config.
  - Fix missing locks in zonemd unit test.
  - Fix static analysis warnings about localzone locks that are unused.
  ...