Implement Web Portal feature.

[nejucomo]

A really simple feature could make Tahoe into a public "web portal". A web portal is a website that presents a given Tahoe directory as it's root url path, for example, these two links would be equivalent:

​http://example.website.com/foo/bar.html ​http://<my tahoe node>/uri/<web portal dir cap>/foo/bar.html

The portal appears like any other website to surfers (aside from headers and performance). The server can run on a system with a tiny disk, and the web site operator need not worry about site backups.

The security implications seem straightforward, given the design of Tahoe.

I haven't looked at the webish code, but I imagine this could be implemented by adding a single configuration setting for the portal dir cap, and then prefixing all URL requests with "/uri/$dircap" before passing the request to the handler.