Sharing a series or season now tags the entire tree (series, seasons,
episodes) so the guest can browse and play everything inside it, and
strips it all again at cleanup. Redeeming re-tags the tree, so episodes
added after the link was created show up on the next redemption. The
guest lockdown in the web client now asks the server whether a page's
item is visible to the guest instead of hard-coding the single shared
id, so guests can navigate inside the shared tree but nowhere else.
Libraries and collections are still rejected.
Bumps the version to 1.0.1.0.