[doc] Added socket checks for the examples

In the examples in awesomerc.5.txt, they kind of assume that awesome is
already running. If you run them from your .xinitrc, they'll fail, because
the awesome socket isn't available.

This patch adds a quick check to make sure the socket is there before
starting up.

Signed-off-by: Julien Danjou <julien@danjou.info>

awesomerc.5.txt

@@ -84,12 +84,21 @@ Simple textbox example
 4. Create ~/bin/awesome-clock
 
     #!/bin/sh
+    while true
+    do
+        # if you start this from .xinitrc, the script will start before
+        # awesome, and will fail.
+        if [ -S ~/.awesome_ctl.0 ]; then
             while true
             do
               echo "0 widget_tell bottom clock text `date`"
               echo "" # an empty line flushes data inside awesome
               sleep 1
             done | awesome-client
+        else
+            sleep 1
+        fi
+    done
 
     Note: What we're saying is "awesome-client, tell the bottom status bar's
     widget named 'clock' to set it's 'text' property to date's output".
@@ -148,12 +157,21 @@ Simple progressbar example
 4. Create ~/bin/awesome-diskusage
 
     #!/bin/sh
+    while true
+    do
+        # if you start this from .xinitrc, the script will start before
+        # awesome, and will fail.
+        if [ -S ~/.awesome_ctl.0 ]; then
             while true; do
                 usage = `df /dev/sda5 | awk '/\/dev\/sda5/ { print 100-$5 }'`
                 echo "0 widget_tell bottom diskusage data disk ${usage}"
                 echo "" # an empty line flushes data inside awesome
                 sleep 600;
             done | awesome-client
+        else
+            sleep 1
+        fi
+    done
 
 
     Note: What we're saying is "awesome-client, tell the bottom status bar's