GlobalReporting

A dirty hack to capture the reported output for the server-mode. Context: server mode is a bit tricky, because the reporting happens inside the repl, but we want to retrieve it from the context outside the repl, and the two have separate classloaders. There's probably a cleaner way, but for now this serves our needs.

Note that this convolutes the output from concurrently-running jobs - so we should not run UserRunnables concurrently.