Add a few more post-release TODO items to the instructions.

Announce the release at isocpp.org.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75188 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Fix assert due to incorrect format being used in listctrl sample.

"%d" can't be used with long wxListEvent::GetIndex() value in 64 bit builds.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75189 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Start a new change log for the changes in wxWidgets 3.1 and later.

Keep the old change log as docs/changes_30.txt, it will need to be updated
with docs/changes.txt from the 3.0 branch in the future.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75190 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Don't eat mouse wheel events if we can't handle them in wxGTK.

The recent changes to mouse wheel scrolling broke it for the generic
wxListCtrl and probably any other situation in which scrollbars don't scroll
the window itself but some subwindow of it. In this case, the scroll wheel
event handler doesn't have any scrollbar to adjust, so it simply does nothing
and shouldn't return true, as it did since r74911.

Just return false in case we are not doing anything to let the mouse wheel
work as before.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75191 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775