Python: Add some missing copyright notices.

setup.py saw quite a few 3rd party contributions.

PsychPython/demos/ppatest_pythonic.py

@@ -6,6 +6,7 @@
 # then plays it back until the end, or until a key is pressed.
 # The test will be subjec to change without notice, it is throwaway test code.
 #
+# (c) 2019 Jon Peirce - Licensed under MIT license.
 # (c) 2018 Mario Kleiner - Licensed under MIT license.
 
 from psychtoolbox import audio, hid
@@ -158,4 +159,4 @@ def run():
     # playback.close()  # PsychPortAudio('Close', pahandle);
 
 if __name__ == '__main__':
-    run()
+    run()

setup.py

@@ -2,6 +2,10 @@
 #
 # (c) 2018-2022 Mario Kleiner
 # (c) 2020-2022 Alex Forrence
+# (c) 2019      Jonathan Peirce
+# (c) 2019      Richard Höchenberger
+# (c) 2019      Eric Larson
+# (c) 2019      Bernhard M. Wiedemann
 #
 # Licensed under the MIT license.
 #