update bundled TightVNC for Windows to version 2.8.8

Author: pinhead84

README.md

@@ -103,15 +103,15 @@ the operating system):
 
 -   for Windows (Vista and newer)
 
-    -   [TightVNC 2.8.5](http://www.tightvnc.com/) (GPLv2) using binaries from
+    -   [TightVNC 2.8.8](http://www.tightvnc.com/) (GPLv2) using binaries from
         [tightvnc.com](http://www.tightvnc.com/download.php)
 
     -   [OpenSSH 7.6p1-1](https://www.openssh.com/) (BSD) using binaries from
         [mls-software.com](https://www.mls-software.com/opensshd.html)
 
 -   for Windows (XP / 2003)
 
-    -   [TightVNC 2.8.5](http://www.tightvnc.com/) (GPLv2) using binaries from
+    -   [TightVNC 2.8.8](http://www.tightvnc.com/) (GPLv2) using binaries from
         [tightvnc.com](http://www.tightvnc.com/download.php)
 
     -   [OpenSSH 7.3p1-2](https://www.openssh.com/) (BSD) using binaries from

src/data/windows-xp/tightvnc/LICENSE.txt

@@ -176,7 +176,7 @@ namespace eval ::support::session {
   # Initialize VNC environment for Windows.
   proc init_windows {} {
     variable VNC_APP_NAME "TightVNC"
-    variable VNC_APP_VERSION "2.8.5"
+    variable VNC_APP_VERSION "2.8.8"
     variable VNC_APP_LICENSE "GPLv2"
 
     variable SSH_APP_NAME "OpenSSH"