the necessary keywords to look them up in the manual, ChangeLog or other
sources of information.
+2005-08-27:
+
+ It's now possible to define and use arbitrary self-defined
+ variables as long as prefixed with user_.
+
+ The $user_agent variable had to be renamed to $agent_string.
+
+ To keep consistency, the -D option has been removed again in
+ favor of -T and -t.
+
2005-08-25:
Instead of only supporting to expand environment variables via