resolve #157 - remove \x8b and \x9b from encoding

these can break unicode strings, and we are more concerned with
those these days than supporting old browsers

update Changes and bump VERSION. mark the module as "done"

Changes

@@ -1,6 +1,10 @@
-4.15 2015-04-20
+4.20 2015-05-29
 
     [ RELEASE NOTES ]
+    - CGI.pm is now considered "done". See also "mature" and "legacy"
+      Features requests and none critical issues will be outright rejected.
+      The module is now in maintenance mode for critical issues only.
+
     - This release removes the AUTOLOAD and compile optimisations from CGI.pm
       that were introduced into CGI.pm twenty (20) years ago as a response to
       its large size, which meant there was a significant compile time penalty.
@@ -49,11 +53,13 @@
     [ FEATURES ]
     - CGI::Carp now has $CGI::Carp::FULL_PATH for displaying the full path to the
       offending script in error messages
-    - CGI now has env_query_string() for getting the value of QUERY_STRING from the
-      environment and not that fiddled with by CGI.pm (which is what query_string()
-      does) (GH #161)
-    - CGI::ENCODE_ENTITIES var added to control which chracters are encoded by the
-      call to the HTML::Entities module - defaults to &<>"\x8b\x9b' (GH #157)
+    - CGI now has env_query_string() for getting the value of QUERY_STRING from
+      the environment and not that fiddled with by CGI.pm (which is what
+      query_string() does) (GH #161)
+    - CGI::ENCODE_ENTITIES var added to control which chracters are encoded by
+      the call to the HTML::Entities module - defaults to &<>"' (GH #157 - the
+      \x8b and \x9b chars have been removed from this list as we are concerned
+      more about unicode compat these days than old browser support.)
 
     [ DOCUMENTATION ]
     - Fix some typos (GH #173, GH #174)