[Rivet] New Rivet bootstrap script

[Frank Siegert]

Hi Andy,
[dropping the Sherpas from this thread via Bcc]

Thanks for the feedback.

> Have the mentions of building from trunk / dev mode now been removed
> from the wiki as David suggested? From a quick scan, I think they're
> gone, but just checking...

There is GettingStartedForDevelopers, of course, but that should be
named clear enough.

> Copying the setup scripts... I didn't think they made much sense *in*
> the install tree: maybe copy them to the $PWD of where the command was
> run? But in truth I don't mind where the bootstrap puts them: wherever
> most people think they will be useful.

My reasoning was, that the env scripts are useful to keep around,
since people will need them later (e.g. to source them from their
bashrc). And if I would be installing something into an installation
prefix I would assume that I can safely delete the build directory
after that.

> The ManualInstallation page: d'oh, I just updated that a few weeks ago!
> Oh well. I thought it was useful to have the procedure documented,

I haven't removed it yet, but thought that it might get out-of-date
quickly again.
What's the use case for the ManualInstallation page? Expert users will
be able to read the bootstrap script (which will be much more
up-to-date and rigorous than any wiki page), and non-experts should
simply use the bootstrap script.

> especially back when the bootstrap script was *very* complex and no-one
> could be expected to reverse engineer what it was doing. I've not
> checked to see if your version is simple enough for an average user to
> read as instructions, or if the dev mode stuff makes it a bit too
> confusing,

The dev mode installation is completely separate at the end, so I
don't think it will be confusing.

Cheers,
Frank