Client not responding to WG of Posn and Size

[mkromberg]

Using the "next" branch, Start GAMA and resize the main form. You will see something like:

17:27.139 T: #3: {"WG":{"ID":"F0000.s","Properties":["Size","Posn"],"WGID":"15"}}
17:30.133 W: Client did not respond within 3 seconds.
17:30.136 W: Request was: {"WG":{"ID":"F0000.s","Properties":["Size","Posn"],"WGID":"15"}}

[mkromberg]

This can also be reproduced using Demo_Issue303