add new options to bip.vim syntax file

add a readme for anti flood systems

README.floodcontrol

@@ -0,0 +1,25 @@
+*** This is a warning about bip's replay/backlog system ***
+
+Bip has a backlogging system which will send back parts of the last logs upon
+client connection. Depending on your configuration, that may mean a *lot* of
+data sent back to your client.
+
+Users' messages will be replayed as if they were being sent at the moment your
+client connects to bip, and if not disabled, system messages will appear as
+coming from the "-bip" user.
+
+Considering that, you may want to disable your client's anti-flood system,
+totally or not, depending on it's flexibility.
+Since bip doesn't relay CTCP messages, you can safely let your client's
+anti-flood system manage them.
+
+[Xchat]
+If you're using Xchat, you can "disable" it by issuing these commands :
+/set flood_msg_num = 1000
+/set flood_msg_time = 10
+In fact you'll tell xchat to activate its anti-flood system when you're
+receiving more than 1000 messages in less than 10 seconds.
+
+If you forgot to set these, private messages may not appear in separate tabs
+as usual. If so, simply issue a :
+/set gui_auto_open_dialog on

samples/bip.vim

@@ -54,6 +54,7 @@ syn region	bipMain		start=/\%^/ end=/\%$/
 " Top level elements
 syn keyword	bipKeyword	contained nextgroup=bipBoolV client_side_ssl
 	\ no_backlog always_backlog bl_msg_only blreset_on_talk
+	\ backlog_no_timestamp backlog
 syn keyword	bipKeyword	contained nextgroup=bipStringV log_root
 	\ log_format pid_file
 syn keyword	bipKeyword	contained nextgroup=bipNumericV port log_level