QWindow: Do not call setters for window state, type etc in creation.

QWindow: Do not call setters for window state, type etc in creation.

Remove the need to do housekeeping and comparison of window types,
etc in the platform window setters. They can safely assume the flags
have really changed and something (potentially recreating the
window) has to be done.
createPlatformWindow() must then query all parameters from
QWindow and apply them.

Change-Id: I497060ba46a955cad1fa3cbb5eb91438a420b80e
Reviewed-on: http://codereview.qt.nokia.com/2198
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>