update syntax file for GNU Screen

update-syntax-for-screen.diff

diff -r 609b7c0be284 runtime/syntax/screen.vim
--- a/runtime/syntax/screen.vim	Tue Apr 29 20:04:09 2014 +0200
+++ b/runtime/syntax/screen.vim	Wed Apr 30 20:45:39 2014 +0900
@@ -81,6 +81,7 @@
                           \ chacl
                           \ charset
                           \ chdir
+                          \ cjkwidth
                           \ clear
                           \ colon
                           \ command
@@ -104,6 +105,7 @@
                           \ deflogin
                           \ defmode
                           \ defmonitor
+                          \ defmousetrack
                           \ defnonblock
                           \ defobuflimit
                           \ defscrollback
@@ -126,7 +128,9 @@
                           \ fit
                           \ flow
                           \ focus
+                          \ focusminsize
                           \ gr
+                          \ group
                           \ hardcopy
                           \ hardcopy_append
                           \ hardcopydir
@@ -157,6 +161,7 @@
                           \ monitor
                           \ msgminwait
                           \ msgwait
+                          \ mousetrack
                           \ multiuser
                           \ nethack
                           \ next
@@ -182,6 +187,7 @@
                           \ register
                           \ remove
                           \ removebuf
+                          \ rendition
                           \ reset
                           \ resize
                           \ screen
@@ -210,6 +216,7 @@
                           \ time
                           \ title
                           \ umask
+                          \ unbindall
                           \ unsetenv
                           \ utf8
                           \ vbell