Merge pull request #12 from blackboard/string-id

Expose job id as a string for ease-of-use
Merge pull request #14 from blackboard/cancel-job

Allow queued jobs to be cancelled, preventing them from running
Merge pull request #16 from blackboard/log-stack

Log stacks for errors as well
Merge pull request #15 from blackboard/index

Create index optionally for poling dequeue query
Lock mongoskin version so it won't auto-upgrade
Merge branch 'mongoskin-version' into blackboard
Bump version