#23539: Set Content-Length to 0 for PUT, POST, and PATCH if body is None.

Some http servers will reject PUT, POST, and PATCH requests if they
do not have a Content-Length header.

Patch by James Rutherford, with additional cleaning up of the
'request' documentation by me.
diff --git a/Misc/ACKS b/Misc/ACKS
index a23b470..cdee1bb 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -1179,6 +1179,7 @@
 Mark Russell
 Rusty Russell
 Nick Russo
+James Rutherford
 Chris Ryland
 Constantina S.
 Patrick Sabin