Add two new public functions to the public C-API,
:c:func:`PyEval_SetProfileAllThreads` and :c:func:`PyEval_SetTraceAllThreads`,
that allow to set tracing and profiling functions in all running threads in
addition to the calling one. Also, two analogous functions to the
:mod:`threading` module (:func:`threading.setprofile_all_threads` and
:func:`threading.settrace_all_threads`) that allow to do the same from Python.
Patch by Pablo Galindo
