made master retry count configurable.
Merge pull request #565 from dcapwell/masterRetryConfig

made master retry count configurable.
handle overflow when retry count gets larger
lower retry to 29
Merge pull request #566 from dcapwell/retryWithLargerValues

handle overflow when retry count gets larger
update docker due to directory hierarchy change
update README
Merge pull request #567 from uronce-cc/dockerUpdate

Docker update
Merge branch 'master' into branch-0.6