Make tmux use C-s as the prefix key

This eases usage with readline and avoids XOFFing your screen everytime
you hit C-s by accident. This change also modifies a couple of key
bindings, such as using C-s C-s to switch to the last window, and C-s
M-k to clear the scrollback history and C-s C-y to toggle pane sync

tmux.conf

@@ -1,7 +1,7 @@
-# Switch prefix to use C-a instead of C-b
+# Switch prefix to use C-s instead of C-b
 unbind-key C-b
-set-option -g prefix C-a
-bind-key a send-prefix
+set-option -g prefix C-s
+bind-key C-q send-prefix
 
 # Use 256 color mode
 set-option -g default-terminal "screen-256color"
@@ -92,7 +92,7 @@ set-option -g message-command-fg $TMUX_MESSAGE_BG
 set-option -g pane-active-border-fg green
 
 # Window switching
-bind-key    C-a last-window
+bind-key    C-s last-window
 unbind-key  l # existing default binding
 
 # Window splitting
@@ -113,7 +113,7 @@ bind-key H \
     display-message 'Toggled logging to ~/tmux_logs/tmux_log.#I-#P'
 
 # Synchronize panes - have a hotkey to switch sync on and off
-bind-key C-s set-window-option synchronize-panes
+bind-key C-y set-window-option synchronize-panes
 
 # Tweak the copy mode bindings
 unbind-key -t vi-copy C-e
@@ -147,9 +147,9 @@ bind-key - \
     kill-window -t tmux-zoom
 
 # Clear history
-# Bash uses C-l to clear the screen, so you can use C-l, C-k to clear the
+# Bash uses C-l to clear the screen, so you can use C-l, M-k to clear the
 # screen and the scrollback buffer too
-bind-key -n C-k clear-history
+bind-key -n M-k clear-history
 
 # Power detach (detach and hangup parent process)
 bind-key D detach-client -P