command-line clarify the --server flag and use a local default

[zooko]

The word "vdrive server" can mean either a tahoe node that exports a vdrive to a client over HTTP or a tahoe node that exports vdrive service to another tahoe node via foolscap. (The former uses the latter for its persistent storage and sharing.)

This should be clarified in the command-line's "--server" option. (It means the former.)

In addition, the default should not be the global public HTTP server, but instead the http://localhost:$WEBPORT server.

Brian: have I misunderstood anything here?

[zooko]

Clarify the call for clarity.

[warner]

Yeah, I think that's right.

I don't thingk we're planning to offer a public HTTP server anytime in the near future. As part of a service offering, we might provide one for customers, but of course we'll need to work out some authentication issues for that.

My thought is that we should establish a default location for a tahoe client node, say ~/.tahoe, and have all of the node start-stop commands use that by default (so 'tahoe start' would expand to 'tahoe start --basedir=~/.tahoe').

The nonce-prefix-in-URL thing we're discussing in #98 could then by used by the cli get/put/ls tools, so 'tahoe ls' would mean "look in ~/.tahoe/webport and and ~/.tahoe/webnonce, derive a localhost URL from that, and use it as the base for all vdrive operations". In this case, the get/put/ls tools could take the same --basedir argument that the node-start-stop commands do, but an explicit --server or --httpserver or something would override the URL computed from the contents of --basedir.

[zooko]

So, since we're really getting down to the wire on v0.5 release, what about making there be no-default-value for --server for now?

[zooko]

Making a nice default value is now ticket #110.

The rest of this ticket is fixed by a couple of patches culminating in 75b10954e4dd7370.