widearea reloading support.
* New slot in the images table to store an access key which remote
sites must provide in order to download an image (via https).
* tmcd returns a different kind of ADDRESS field from doloadinfo.
Instead of the multicast stuff, return a URL that points to boss'
web server. The URL is of the form:
which as you can see is fully specified; the client does not need
to know anything else.
* New webpage and backend scripts appropriately called "spewimage"
which also includes support for the http HEAD request (from wget) to
avoid downloading images that are already on the node. I just
learned about this HEAD request stuff today ... but otherwise these
operate as expected, spewing the image if the access key is provided.
* Changes to rc.frisbee to deal with remote loading. In addition to
URL support, I also added support for simple paths, the intent being
that we will probably distribute images offline (say, at night) so
that when a node reboots it doesn't actually have to wait 60 minutes
for an image to download. I have not added any server side support
for this yet though. Maybe later this week.
* Other bits and pieces and fixes to make this work.