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/roundup/configuration.py	Sat Oct 16 21:34:14 2021 -0400
+++ b/roundup/configuration.py	Mon Oct 18 20:12:09 2021 -0400
@@ -639,6 +639,16 @@
         return value
 
 
+class HttpVersionOption(Option):
+    """Used by roundup-server to verify http version is set to valid
+       string."""
+
+    def str2value(self, value):
+        if value not in ["HTTP/1.0", "HTTP/1.1"]:
+            raise OptionValueError(self, value, "Valid vaues for -V or --http_version are: HTTP/1.0, HTTP/1.1")
+        return value
+
+
 class RegExpOption(Option):
 
     """Regular Expression option (value is Regular Expression Object)"""