4.17.1

- Add typecheck to prevent Gtk-CRITICAL (Issue #63)
- Initialize `modifier` at the time of declaration
- Remove redundant code
- Fix AC_LANG_SOURCE macro
- Fix `G_UNLIKELY` check
- Fix memory leak
- exo_strdup_strftime: Support additional encoding (Issue #66)
- exo-die: Add trusted flag support
- Translation Updates:
  Catalan, Galician, Indonesian, Kazakh, Spanish