After a deep refactoring, finally finished to split the window manager

After a deep refactoring, finally finished to split the window manager
in a parent class and a child with hildon1 specific behavior. This way I
will be able to implement a hildon2 based window manager.

Responsibility of window manager:
    * Hibernation management.
    * Preregistered UIDs
    * Preload cache for view and editor.
    * Banners counting
    * Fetching help id's
    * In registering process, the part of removing the uid from
      preregistered uids list.
    * Keeping a reference to main window.
    * Saving window states.
    * Counting number of windows (maintaining the list is responsibility
      of children).

Responsibility of child:
    * Implementation of close all windows.
    * In finding registered headers, checking also in windows.
    * Show toolbar status.
    * Fullscreen status.
    * Registering window stuff (in particular also related to message
      changes in view).
    * Destroy operations, and cancelling operations on close window.
    * Fetching the main window implementation.
    * Maintaining the list of modal dialogs.

pmo-trunk-r5966