[gobject-introspection] Created tag 1.59.3

[Christoph Reiter <creiter src gnome org>]

The signed tag '1.59.3' was created.

Tagger: Christoph Reiter <reiter christoph gmail com>
Date: 1546961922 +0100

    release 1.59.3

Changes since the last tag '1.59.2':

Christoph Reiter (11):
      version bump
      meson: warn that not all tests will be run if building without cairo/doctool
      meson: remove an unused helper script
      meson: set libdir/bindir relative to exec_prefix
      scanner: rework source root guessing code
      ci: use the pkg-config.exe hosted by meson since sourceforge is flaky
      meson: use underscore as a separator in build options
      get_source_root_dirs: handle empty file list case. Fixes #257
      tests: add some tests for get_source_root_dirs
      Update glib annotations
      release

Mark Nauwelaerts (1):
      website: add cppgir C++ binding

Tomasz Miąsko (5):
      scanner: Merge basic types in `specifier_qualifier_list` production.
      scanner: Merge specifiers and qualifiers when merging basic types.
      scanner: Remove incorrect c:type from fields with array type
      scanner: Remove incorrect c:type generated for array of synthesized unions
      scanner: Flatten multi-dimensional arrays fields