update docs

+ version()
+ $abiversion
+ parse_special()

docs/perl.txt

@@ -205,6 +205,12 @@ Window::command(cmd)
 Windowitem::command(cmd)
   Send a command `cmd' (in current channel). The '/' char isn't needed.
 
+version() - return client release date and time (format YYYYMMDD.hhmm)
+
+parse_special(cmd, data="", flags=0)
+Server::parse_special(cmd, data="", flags=0)
+Windowitem::parse_special(cmd, data="", flags=0)
+  evaluate a string with special vars
 
  *** Themes
 

docs/special_vars.txt

@@ -94,6 +94,8 @@ $A .. $Z is important.
    $winname             window name
    $itemname            like $T, but use item's visible_name which may be
                         different (eg. $T = !12345chan, $itemname = !chan)
+   $abiversion          IRSSI_ABI_VERSION
+                         https://github.com/irssi/irssi/wiki/irssi_abi_version
 
 For example, assume you have the following alias: