Specifically, output of "cvs ci" varies unpredictably across CVS versions,
so any test that includes the output of "cvs ci" is doomed to fail
some of the time. This fixes that by discarding the output of "cvs ci".
Source and destination constructors should be fast so configurations issues are
hit quickly, including authentication and filemap/authormap/splicemap issues.
Delaying might be a problem if the remove side disconnects idle connections
while the log is being read. It did not happen when converting openafs
repository, where log retrieval took at least 10mn.