Add new tmux config for CentOS 6 clients

I'm sick of seeing errors like these at startup on my CentOS 6 boxes:

/home/aorth/.tmux.conf: 111: unknown option: window-status-bell-attr
/home/aorth/.tmux.conf: 112: unknown option: window-status-bell-fg

.tmux.conf_centos6

@@ -0,0 +1,116 @@
+unbind C-b
+set-option -g prefix ^A
+bind a send-prefix
+
+# Bind appropriate commands similar to screen.
+# lockscreen ^X x
+unbind ^X
+bind ^X lock-server
+unbind x
+bind x lock-server
+
+# screen ^C c
+unbind ^C
+bind ^C new-window
+unbind c
+bind c new-window
+
+# detach ^D d
+unbind ^D
+bind ^D detach
+
+# displays *
+unbind *
+bind * list-clients
+
+# next ^@ ^N sp n
+unbind ^@
+bind ^@ next-window
+unbind ^N
+bind ^N next-window
+unbind " "
+bind " " next-window
+unbind n
+bind n next-window
+
+# title A
+unbind A
+bind A command-prompt "rename-window %%"
+
+# other ^A
+unbind ^A
+bind ^A last-window
+
+# prev ^H ^P p ^?
+unbind ^H
+bind ^H previous-window
+unbind ^P
+bind ^P previous-window
+unbind p
+bind p previous-window
+unbind BSpace
+bind BSpace previous-window
+
+# windows ^W w
+unbind ^W
+bind ^W list-windows
+unbind w
+bind w list-windows
+
+# kill K k
+unbind K
+bind K confirm-before "kill-window"
+unbind k
+bind k confirm-before "kill-window"
+
+# redisplay ^L l
+unbind ^L
+bind ^L refresh-client
+unbind l
+bind l refresh-client
+
+# " windowlist -b
+unbind '"'
+bind '"' choose-window
+
+# use Escape for entering copy mode, like screen
+bind Escape copy-mode
+
+# less time between commands in a command sequence
+set -s escape-time 0
+
+# use vi-style key bindings
+set-option -g mode-keys vi
+
+# start numbering windows a 1
+set -g base-index 1
+
+# Rather than constraining window size to the maximum size of any client
+# connected to the *session*, constrain window size to the maximum size
+# of any client connected to *that window*. Much more reasonable.
+set-window-option -g aggressive-resize on
+
+# the visual bell causes a micro delay when typing. Tab completion triggers
+# the bell and typing halts for a second and it's really annoying.
+set-option -g visual-bell off
+
+# status bar
+set-option -g status-justify left
+set-option -g status-bg blue
+set-option -g status-fg white
+set-option -g status-left ''
+set-option -g status-right '#[fg=colour47]#H #[fg=red]#(cut -d " " -f 1-3 /proc/loadavg) #[fg=colour227]%Y-%m-%d %H:%M#[default]'
+
+# terminal messages, like "bell in terminal 1"
+set-option -g message-fg black
+set-option -g message-bg white
+
+# Highlight active window
+set-window-option -g window-status-current-fg white
+set-window-option -g window-status-current-bg red
+
+# scrollback buffer
+set-option -g history-limit 4096
+
+# hijack the TERM variable for shells inside tmux
+set-option -g default-terminal "screen-256color"