* Control.cs: Call ContainerControl.ChildControlRemoved whenever a

* Control.cs: Call ContainerControl.ChildControlRemoved whenever a
  control is removed from a control collecftion.
* XplatUIX11.cs: The first location for toplevel form is (22, 22).
  Fixes FormPropertyTest (failed on rare occasions).
* XplatUIWin32.cs: Add a workaround in SetParent for strange behaviour
  of Win32SetParent (when changing from no parent to a parent it
  might add the new parent's location in screen coordinates to this
  window's location).
* Form.cs: Rework ChangingParent once again, now the handle is
  recreated whenever a FormWindowManager is added or removed (that is
  whenever a normal form is parented or abandoned). Also change
  CreateParams so that all non-toplevel windows always get the
  specified sice (StartupPosition is never considered for
  non-TopLevel forms).
* ContainerControl.cs: Add ChildControlRemoved, the container control
  needs to be notified when a control is removed from it's
  collection, in the case the removed control is the active control.
* Hwnd.cs: Completely reworked GetWindowRectangle and
  GetClientRectangle - they are now passed a CreateParams and they
  only use Style and ExStyle to determine the rectangles (they should
  now work just like Win32AdjustWindowRectEx - though quite a few
  special cases are probably missing). They should also be 100%
  complimentary (i.e. GetWindowRectangle (GetClientRectangle (rect))
  == rect), and all numbers (borders, menu sizes) are taken from the
  current theme. Added a GetBorders helper function that will return
  the borders for any given CreateParams (including captions and
  menus), and GetBorderSize that returns the given border size only.

svn path=/trunk/mcs/; revision=75287