themes: default set a default wallpaper if possible

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

awesomeConfig.cmake

@@ -276,6 +276,7 @@ set(AWESOME_THEMES_PATH      ${AWESOME_DATA_PATH}/themes)
 set(AWESOME_CONFIGURE_FILES
     config.h.in
     awesomerc.lua.in
+    themes/default.in
     lib/awful.lua.in
     awesome-version-internal.h.in
     awesome.doxygen.in)

themes/default.in

@@ -19,7 +19,7 @@ border_marked = #91231c
 
 # You can use your own command to
 # set your wallpaper
-wallpaper_cmd = xsetroot -solid darkgrey
+wallpaper_cmd = xsetbg -fullscreen -border black @AWESOME_THEMES_PATH@/default-background.png || xsetroot -solid darkgrey
 
 # You can add as many variables as
 # you wish and access them by using