better use if semaphore in S3 auth provider
Fix an error in chunk size calculation
Merge /Users/johnclay/Clients/TrialGuides/Source/ProFolio/Ext/Cumulus
#20 cancel all chunks, not just running ones
Closes #21, proper handling of query object and query strings
Allow callers to set the min progress update interval
Updating specs to run with some new changes and additions