Alternate versions, member links and a demo reel builder

Added

• Alternate Versions: an extended cut, alternate edit or trailer can hang off a film.
• Member links and bio.
• Demo reel builder.
• A branded signup page and invitation email.

Changed

• Portfolio, KTL TV and media folded into one video type.
• Header profile dropdown simplified.
• Removed the “Who can watch?” control on films.

Fixed

• Member invitations now work end to end, and site email stopped landing in spam.
• Two membership bugs, including one that locked out real members.