Add "play online" links to all story files with supported web interpreters

[salty-horse]

The External Links section has several usability problems regarding Play Online.

1. Only the first link marked "This is a playable game file or it contains a playable game" gets a Play Online link. This "Play Online" link is the only way story files gets wrapped up with web interpreters for easy use. Visitors who don't want to mess with running games locally, or don't have sufficient know-how to point iplayif at the provided files, have no way of trying those additional files.

2. When editing an external link, the bottom of the dialog box says:

   According to the settings above, this link will include a "Play On-line" button.

   This is not always true. If the game the second such-marked file, it will not get a button. (BTW, the hyphen should be removed).

I think that all playable links that have web interpreters (Parchment-capable or ADRIFT) should get a "Play online" link next to them. It doesn't need to be as prominent as the regular "Play online" button.

[salty-horse]

A curious situation where this is relevant is The Purple Pearl - A 2-player game with two different gblorb files. Neither game is marked as playable, I assume so there won't be a "play online" button for just one of them.

So maybe there should be a way to disable the main "play online" button, but still be able to mark individual links as playable, with their own buttons.