DVD menu highlights are not always shown

[peper03@…]

Menu highlights for menus in the VTS domain are not always shown as the stream ID is only set if there is at least one button when the subpicture stream change notification arrives but it not possible to know how many buttons are available until a NAV packet arrives, so the stream ID is not set.

The attached patch sets of the stream ID when the first NAV packet with button information arrives. It also cleans up the code responsible for detecting a looping menu (so that the selected button is not changed when the loop restarts), which also didn't work with menus in the VTS domain.

A sample DVD image (DelayedMenu_VTS.iso) is available in stuartm's DVD repository.

[Richard <peper03@…>]

In 6fce2124610e1b5e971e58248717bd3927e785ef/mythtv:

VTS title and clean up menu looping detection.

Querying the number of buttons as soon as a subpicture stream change
notification appears is generally not possible as the button
information is carried in NAV packets, which probably haven't been
read yet.

Fixes #11445

Signed-off-by: Stuart Morgan <smorgan@…>