Avoid calling SetSize() from wxCompositeWindow::Create() under wxGTK.

This was unexpected and resulted in a crash in the case of wxDatePickerCtrl.
And while this particular crash could be fixed just by checking for the
pointers validity in the overridden wxDatePickerCtrl::SetSize(), it seems
better to avoid such unexpected calls to SetSize(), especially as they only
happen under wxGTK, which calls SetLayoutDirection(wxLayout_Default) from its
wxWindow::Create(), and so wouldn't be found by any amount of testing under
other platforms.

Closes #16589.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77890 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Revert "Skip mouse button release events in wxGenericTreeCtrl."

This reverts r76094 as it broke label editing in the control.

See #16055, closes #16573.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77891 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Don't prevent the other button release handlers from running in wxGTK.

There doesn't seem to be any advantage in doing this, but it can result in
problems see #16055. So just always let the other handlers for this event
execute as well, even if we did process it.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77892 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Revert "Skip mouse button release events in wxGenericListCtrl."

This reverts r76824 as it is not necessary any longer, the fix in the previous
commit takes care of this problem more generally.

See #16365.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77893 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775