Fixed MaximizablePanel in Chrome

In Chrome the contents of the Ext.Window derived panel where overlapped
after a 'maximize' command. One had to click on the hidden elements to
reveal them.

The panel no longer gets rendered to the element provided in the
'renderTo' config, but always to the body element. All size and position
operations are still made on 'renderTo'.

Also added logic to update absolute position on window resize

Change-Id: I566854f49f9a4bdeb5a61249c6c99f72f28ed43d
Merge "Fixed MaximizablePanel in Chrome" into REL1_22