Redirect /jxtx/ to jxtxfoundation.org and reorganize images.

[NickSto]

As requested by @nekrut, we'll be redirecting /jxtx/ to the official Foundation page.

This also moves some of the related images to more appropriate locations.

[tnabtaf]

Hi @NickSto,

1. /jxtx/bio/ should redirect to jxtxfoundation.org/james
2. and /jxtx/{memorials,stories,we-miss-you} are no longer pointed to from anywhere. They also aren't reproduced on the JXTXFoundation site.

@nekrut Should we drop those last 3 pages? We could add links to them from various James news items, if want to keep them around and linked to.

[NickSto]

Yeah I didn't know what to do with those 3 pages. It seems like pretty valuable stuff that'd be a shame to lose.