Installer flows

[Rod Widdowson]

> In your first case, a new install, it's got to be missing both
> idp.properties and relying-party.xml, right?

Yea, or the directory ain't there (see below)

 > Maybe it should just look at the installation directory and if it exists
> already, it's one of the other cases, no guessing.

I think so.  It’s the safe approach.
 
> In the upgrade case, maybe we should just save off war and credentials
> also in .old directories, and then instead of editing the config to use
> the old key/cert names, we copy from the old ones into the new credentials
> directory.

I like that.  

One thing that did strike me this morning is undoing all this.  This will
happen if the install fails or the user uninstalls.   This is a damned if
you do damned if you don't case:  if the install fails the user might want
to get back their V2 config, but if the install is removed you want to leave
V3 config in place.  My conclusion is that we should not do any undo of the
renames, once we have gone 2->3 that sticks.  If someone wants to go back
they still have all the configuration and they can do that by hand.  We may
want to add another screen for the 2-3 Case "do you want to", but I suspect
that we'd be better an upgrade.txt output saying what has been done.

As a brief status I have the GUis in place - I still need to add the capture
of specific information for new installs and the dynamic capture of what
sort of install we have as a result of the selection of a target dir.

I'm going to move my attention now to the mechanics of the upgrade - which
mostly means the ant file. I already have a class in place to allow the edit
of idp.properties while retaining comments.

R