Fix background of wxRadioBox buttons and wxSlider labels in wxMSW.

Handle WM_CTLCOLOR correctly for them, this wasn't done before because the
code assumed that sub-windows (i.e. HWNDs which belong to the same logical wx
control) were always children of the main window, but they could also be its
siblings (like in at least the two above mentioned cases).

Account for this case in wxControl::DoMSWControlColor() too now.

Closes #12271.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76950 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
Write delay between frames correctly when saving GIF files.

Deal with delays greater than ~2.5s correctly, their most significant byte was
previously lost resulting in 0 delay being written to the file.

Closes #16392.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76951 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775