Switch to non-deprecated thread and mutex APIs when using GLib >= 2.31.
Switch to non-deprecated thread and mutex APIs when using GLib >= 2.31.

rhaberkorn/scintilla-mirror,rhaberkorn/scintilla-mirror,rhaberkorn/scintilla-mirror,rhaberkorn/scintilla-mirror,rhaberkorn/scintilla-mirror,rhaberkorn/scintilla-mirror,rhaberkorn/scintilla-mirror,rhaberkorn/scintilla-mirror