examples/python: drop nmex.py

It's not an example and not actually used.

https://github.com/NetworkManager/NetworkManager/pull/141

examples/python/nmex.py

@@ -1,72 +0,0 @@
-#!/usr/bin/env python
-# -*- Mode: Python; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
-# vim: ft=python ts=4 sts=4 sw=4 et ai
-
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2 of the License, or
-# (at your option) any later version.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program. If not, see <http://www.gnu.org/licenses/>.
-#
-# Copyright 2018 Red Hat, Inc.
-
-###############################################################################
-# nmex.py contains helper functions used by some examples. The helper functions
-# should be simple and independent, so that the user can extract them easily
-# when modifying the example to his needs.
-###############################################################################
-
-def _sys_clock_gettime_ns_lazy():
-    import ctypes
-
-    class timespec(ctypes.Structure):
-        _fields_ = [
-                ('tv_sec', ctypes.c_long),
-                ('tv_nsec', ctypes.c_long)
-        ]
-
-    librt = ctypes.CDLL('librt.so.1', use_errno=True)
-    clock_gettime = librt.clock_gettime
-    clock_gettime.argtypes = [ctypes.c_int, ctypes.POINTER(timespec)]
-
-    t = timespec()
-    def f(clock_id):
-        if clock_gettime(clock_id, ctypes.pointer(t)) != 0:
-            import os
-            errno_ = ctypes.get_errno()
-            raise OSError(errno_, os.strerror(errno_))
-        return (t.tv_sec * 1000000000) + t.tv_nsec
-    return f
-
-_sys_clock_gettime_ns = None
-
-# call POSIX clock_gettime() and return it as integer (in nanoseconds)
-def sys_clock_gettime_ns(clock_id):
-    global _sys_clock_gettime_ns
-    if _sys_clock_gettime_ns is None:
-        _sys_clock_gettime_ns = _sys_clock_gettime_ns_lazy()
-    return _sys_clock_gettime_ns(clock_id)
-
-def nm_boot_time_ns():
-    # NetworkManager exposes some timestamps as CLOCK_BOOTTIME.
-    # Try that first (number 7).
-    try:
-        return sys_clock_gettime_ns(7)
-    except OSError as e:
-        # On systems, where this is not available, fallback to
-        # CLOCK_MONOTONIC (numeric 1).
-        # That is what NetworkManager does as well.
-        import errno
-        if e.errno == errno.EINVAL:
-            return sys_clock_gettime_ns(1)
-        raise
-def nm_boot_time_us():
-    return nm_boot_time_ns() / 1000
-def nm_boot_time_ms():
-    return nm_boot_time_ns() / 1000000
-def nm_boot_time_s():
-    return nm_boot_time_ns() / 1000000000
-
-###############################################################################