Fix Ecore evas extn for multi client model.

Fix Ecore evas extn for multi client model.
It is possible that several process want to show same canvas.
For support this, I changed Ecore buffer canvas to server(socket)
If some application want to show this canvas,
it create plug image object.

git-svn-id: svn+ssh://svn.enlightenment.org/var/svn/e/trunk/ecore@66892 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33