Add full parsing of program pages

This commit enables full parsing of program pages so that both episodes and clips are listed
as results. This, however, introduces another level of navigation.
Patch 1

This time we parse the "clips" tab if the "episodes" tab is missing. This does not, however, enable the user to access all the content from the website.
Patch 2

Add the setting option to show episodes and clips pages for programs.
Default, the plugin will only show the episodes but if there are no episodes it will fallback to show the clips.
Patch 3