Using bitmaps of preferred size avoids scaling and results in much
better appearance, so add methods allowing querying the bundle about the
bitmaps it supports and implement them in the various implementations.
This is not actually used anywhere yet, but will be soon.
Existing code may call functions taking wxBitmap with wxIcon, due to an
existing conversion from wxIcon to wxBitmap, so we need to provide a
similar conversion to wxBitmapBundle for compatibility.
Pass wxSize by const reference instead of "const" value.
Note that passing wxSize by value might be not such a bad thing,
actually, but we use const reference for it everywhere else, so do it
here as well for consistency (and the original intention was to do it
like this, missing "&" was just a typo subsequently propagated through
copy-pasting).
No real changes.
This first version provides only a generic implementation of
wxBitmapBundle using a collection of bitmaps and only supports using it
in wxToolBar in wxMSW and wxGTK.
More methods of creating wxBitmapBundle will be provided later and more
functions taking wxBitmap will be changed to take wxBitmapBundle later
too and, of course, all the other ports will be updated to use the new
API too.
