GLib 2.37.4 Unstable Release Repairs Seven Bugs

GLib 2.37.4 fixes a g_source_add_child_source() segfault, fixes various issues with the documentation, repairs inconsistency of G_STRFUNC, and adds missing G_BEGIN/END_DECLS function in the gsettingsschema.h file. Moreover, new private macros were made to interact better with versioning macros, GDBusConnection has been tweaked to be more responsive with async GetAll, and the g_spawn_async() function keeps child_pid_report_pipe open in child process.