remove useless invocations of awful.client.moveresize()

in most themes this is not required - changing the border_size will
reposition the window to accompany the changed total size.

Also the useless resizes do hurt terminals if some of the "window size
changed" events got lost or garbeled. Also some reported lags (awesome
bug FS#1181 - Clients resize lag).
Merge pull request #42 from klaernie/master

remove useless invocations of awful.client.moveresize()