Make sure time.strptime only accepts strings (and document the fact like
strftime). Already didn't accept bytes but make the check earlier. This also
lifts the limitation of requiring ASCII.

Closes issue #5236. Thanks Tennessee Leeuwenburg.
diff --git a/Misc/ACKS b/Misc/ACKS
index 85bc8a1..85a443b 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -411,6 +411,7 @@
 Inyeol Lee
 Thomas Lee
 Christopher Lee
+Tennessee Leeuwenburg
 Luc Lefebvre
 Kip Lehman
 Joerg Lehmann