Support for default tool and redirect

[Paul Everitt]

Moderators can select a tool to be the default tool of a community.

KARL3 Behavior
===============

We're just going to do a redirect. The /community/africa will go to Overview.

KARL2 Behavior
==================

This is how it works in KARL2. A URL such as:

  /communities/africa

...goes to the default tool. If the default tool is Overview, then this "default" URL returns the same results as clicking on the Overview tab, which leads to the view.html URL.

Stated differently, for a new community, both of these return the same results:

  /communities/africa
  /communities/africa/view.html

The hard part: this works without a redirect. That is, the first URL doesn't redirect you to the second.

If you edit the community and choose Blog as the default tool, then these two URLs return the same result:

  /communities/africa
  /communities/africa/blog

Again, this works without a redirect.

This might be hard to do in KARL3, where the default view is wired up in ZCML, not associated at runtime.

[Paul Everitt (paul-agendaless)]

Assigning to Chris for input. We don't have to address this now, I put it in M4.

[Chris McDonough (chrism-plope)]

Why would anyone care if it redirected or not?

[Chris McDonough (chrism-plope)]

Paul did the default tool stuff; I did the redirect.