[awful] client_moveresize(+/- x-offset, +/- y-offset, +/- width, +/- height)

e.g.:
awful.client.moveresize(10, 0, 0, 0) --increase x-offset by 10 pixels -> moves it to the right
awful.client.moveresize(0, 0, -10, 0) --decreases width of client by 10 pixels

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

awful.lua

@@ -73,6 +73,17 @@ function client_swap(i)
     end
 end
 
+-- Move/resize a client relativ to current coordinates.
+function client_moveresize(x, y, w, h)
+    local sel = client.focus_get()
+    local coords = sel:coords_get()
+    coords['x'] = coords['x'] + x
+    coords['y'] = coords['y'] + y
+    coords['width'] = coords['width'] + w
+    coords['height'] = coords['height'] + h
+    sel:coords_set(coords)
+end
+
 function screen_focus(i)
     local sel = client.focus_get()
     local s
@@ -342,6 +353,7 @@ P.client =
     movetotag = client_movetotag;
     toggletag = client_toggletag;
     togglefloating = client_togglefloating;
+    moveresize = client_moveresize;
 }
 P.screen =
 {