Issue #298 - Set the imei property when saving a DeviceSurveyJobQueue

* The imei property needs to be defined for a property lookup
Issue #300 - Convert EOL char to unix

* It's just EOL change, no other code change has been introduced
Issue #300 - Remove trailing white space
Issue #300 - Generate GWT code only for WebKit browsers
Issue #303 - Check the MD5 checksum to ensure a successful upload to S3

* Generate a MD5 checksum for each file uploaded to Amazon S3, to be
compared with the one returned in the etag.
* Parse HTTP response to extract the etag located in 'Location' header.
* Close HttpURLConnection to release its resources.
* Clean up - use List interface for declarations instead of ArrayList implementation.
Issue #310 - Secure calls to testharness servlet

* The calls to /webapp/testharness are now secured and
  the user requires `SUPER_ADMIN` role
Issue #305 - Implement duplicated QAS removal

* Adds a way to remove the duplicated QAS entities `questionID -
  surveyInstanceId` using the testharness
* It uses the configured backend for processing
Merge branch 'develop' into feature/231-229