+! wxWindow::m_font and m_backgroundColour/m_foregroundColour are no longer
+ always set, use GetFont(), GetBack/ForegroundColour() to access
+ them, and they will be dynamically determined if necessary.
+
+
+! The Sizers have had some fundamental internal changes in the 2.5.2
+ and 2.5.3 releases intended to make them do more of the "Right
+ Thing" but also be as backwards compatible as possible. First a bit
+ about how things used to work:
+
+ * The size that a window had when Add()ed to the sizer was assumed
+ to be its minimal size, and that size would always be used by
+ default when calculating layout size and positions, and the
+ sizer itself would keep track of that minimal size.
+
+ * If the window item was Add()ed with the wxADJUST_MINSIZE flag
+ then when layout was calculated the item's GetBestSize would be
+ used to reset the minimal size that the sizer used.
+
+ The main thrust of the new Sizer changes was to make behaviour like
+ wxADJUST_MINSIZE be the default, and also to push the tracking of
+ the minimal size to the window itself (since it knows its own needs)
+ instead of having the sizer take care of it. Consequently these
+ changes were made:
+
+ * The wxFIXED_MINSIZE flag was added to allow for the old
+ behaviour. When this flag is used the size a window has when
+ Add()ed to the sizer will be treated as its minimal size and it
+ will not be readjusted on each layout.
+
+ * The min size stored in wxWindow and settable with SetSizeHints or
+ SetMinSize will by default be used by the sizer (if it was set)
+ as the minimal size of the sizer item. If the minsize was not
+ set (or was only partially set) then the window's best size is
+ fetched and it is used instead of (or blended with) the minsize.
+ wxWindow:GetBestFittingSize was added to facilitate getting the
+ size to be used by the sizers.
+
+ * The best size of a window is cached so it doesn't need to
+ recaculated on every layout. wxWindow::InvalidateBestSize was
+ added and should be called (usually just internally in control
+ methods) whenever something is done that would make the best
+ size change.
+
+ * All wxControls were changed to set the minsize to what is passed
+ to the constructor or Create method, and also to set the real
+ size of the control to the blending of the minsize and bestsize.
+ wxWindow::SetBestFittingSize was added to help with this,
+ although most controls don't need to call it directly because it
+ is called indirectly via the SetInitialSize called in the base
+ classes.
+
+ At this time, the only situation known not to work the same as
+ before is the following:
+
+ win = new SomeWidget(parent);
+ win->SetSize(SomeNonDefaultSize);
+ sizer->Add(win);
+
+ In this case the old code would have used the new size as the
+ minimum, but now the sizer will use the default size as the minimum
+ rather than the size set later. It is an easy fix though, just move
+ the specification of the size to the constructor (assuming that
+ SomeWidget will set its minsize there like the rest of the controls
+ do) or call SetMinSize instead of SetSize.
+
+ In order to fit well with this new scheme of things, all wxControls
+ or custom controls should do the following things. (Depending on
+ how they are used you may also want to do the same thing for
+ non-control custom windows.)
+
+ * Either override or inherit a meaningful DoGetBestSize method
+ that calculates whatever size is "best" for the control. Once
+ that size is calculated then there should normally be a call to
+ CacheBestSize to save it for later use, unless for some reason
+ you want the best size to be recalculated on every layout.
+
+ * Any method that changes the attributes of the control such that
+ the best size will change should call InvalidateBestSize so it
+ will be recalculated the next time it is needed.
+
+ * The control's constructor and/or Create method should ensure
+ that the minsize is set to the size passed in, and that the
+ control is sized to a blending of the min size and best size.
+ This can be done by calling SetBestFittingSize.
+
+