Merge pull request #59 from kimyen/develop

add util class and test to merge TimeDataPoint lists
Merge pull request #60 from kimyen/develop

Develop
Merge pull request #61 from kimyen/develop

Certified Users Metrics
Merge pull request #62 from kimyen/develop

Fix Bugs and Modify Correct/Incorrect Responses Metrics
Upgrade Vagrant Debian version. Use NFS for better Vagrant performance. Upgrade guest hardware configuration.
Upgrade package versions.
Merge pull request #63 from kimyen/develop

Question Pass/ Fail Metrics
Merge pull request #64 from eric-wu/vagrant

Upgrade Vagrant Debian version. Use NFS for better Vagrant performance. ...
Merge pull request #65 from eric-wu/upgrade

Upgrade package versions.
Replace deprecated DefaultHttpClient.
Merge pull request #66 from eric-wu/upgrade

Replace deprecated DefaultHttpClient.
accept syn* for entityId
add methods to get all file download history