Avoid skipping intro if session started during intro?

[sprt]

This would, as a consequence, avoid skipping the intro in these scenarios:

• When resuming an episode from Continue Watching when the user was previously viewing the intro for some reason. (This can happen if the user came back to the intro -- for whatever reason -- after Skippex skipped it.)
• Untested, but probably when the user switches from say the Plex Web App to a Chromecast during the intro.
• If in the future we decide to automatically restart the program after a crash, then we wouldn't skip forward if the crash happened during the intro.
• Prevents from skipping forward in the middle of a show if Skippex was just started.

Just food for thought, not sure if I wanna implement this. Also, the above list will probably grow.

Risks:

• For new users who have shows in Continue Watching that are currently seeked within the intro, Skippex wouldn't skip the intro when they resume playback at that position. This could lead new users to believe Skippex isn't working properly, so let's clearly document this if we make it happen.