fixes issue couchbase/couchbase-lite-java/issues/25

By throttling Batcher processing of large input queues
issue couchbase/couchbase-lite-java/issues/25

Added some explanatory comments around the calculation of the scheduler delay to use when submitting a batch job
Issue #25 add verbose logging

http://github.com/couchbase/couchbase-lite-java/issues/25
Merge branch 'refs/heads/feature/portable_java_issue_25' into release/1.0.0