Comment 32 for bug 1335323

This sounds good. However, we should probably offer something more elaborate than reinitialize-source-registry-and-retry, and offer the choice between (a) a low-level RETRY restart that lets the handler choose exactly what to reinitialize or not to reinitialize, and (b) a "reset everything then retry" option that calls clear-configuration, clrhash the cache (except for asdf itself?), etc., and then retries.