Enable HTTP/1.1 support for roundup-server This enables keepalives and seems to prevent a lot of hangs/slowness in my configuration. configuration.py: add new HttpVersionOption. This is used by the command line/config in roundup-server. Validates http version string. roundup-server.py: enable HTTP 1.1 by default. use -V to set HTTP/1.0 on command line or set http_version in config file. Fix typo in config description for option include_headers. Add more vertical spacing for error report and usage display. roundup-server.1: add doc on -V also doc -I which was missing. Remove uneeded "to" from a sentence on ssl.

--- a/CHANGES.txt	Sat Oct 16 21:34:14 2021 -0400
+++ b/CHANGES.txt	Mon Oct 18 20:12:09 2021 -0400
@@ -48,6 +48,10 @@
   responsive templates already have this feature.
 - issue2550917 - Add a: "Welcome user, you have logged in" ok_message
   on login. (Ashley Burke)
+- enable HTTP/1.1 for roundup-server. This enables keep-alive for
+  faster response/loading. Also eliminates stalls when the front end web
+  server uses http 1.1 but the roundup-server uses 1.0. New option
+  "-V HTTP/1.0" can turn it off. (John Rouillard)
 
 2021-07-13 2.1.0