Added support for registering WAR files

It requires `get-tmp-copy-of-resource` function from `clj-kitchensink` project - see https://github.com/puppetlabs/clj-kitchensink/pull/36. I'm not sure how versions are currently handled. I suppose that `trapperkeeper-webserver-jetty9` should depend on a higher version of `clj-kitchensink` now.