Add api version to root url response

[jguiditta]

Factory provide something like below, which is handy, and I think we should have something similar:
{"version": "1.1.2_398_gc7a752e", "name": "imagefactory", "api_version": "2.0"}

This would allow us to more easily debug when that is necessary, and it would also make it possible to say 'version xyz of tim works with version abc or greater of factory