Deal with DaRIS component versions better

[crawley]

Currently, there is an ugly ruby hash that maps from a DaRIS version to the version numbers of the downloadable components. Unfortunately, this needs to be updated manually each time the DaRIS team updates their component version numbers ... or else the recipe breaks!

We really need something to extract the actual download version information from the DaRIS site. Either we need to "screen scrape" the URLs (yuck!) or lean (harder!) on the DaRIS team to expose the version numbers as XML or JSON or something else that we can download.