Improve offlineTests error reporting

 - put the ivy repo report in separate spot for dist and
   integration-tests instead of one overwriting the other
 - dump prolems, evictions, artifacts in addition to deps
   to the report
 - when offlineTests fails, helpfully print where the report
   lives and which tests failed
Use non-uuid names in target/ for offline project updates

This way people can manually mess with the test projects
and debug problems.
Collect all errors from offline tests and show them at end

This way you don't have to scroll back through loads of junk.
Log the offline test sbt command
Merge pull request #613 from typesafehub/wip/havocp-offline-reporting

Make offlineTests easier to debug