Issue #427 - implement requireDoubleEntry flag
Issue #427 - fix requireDoubleEntry field in XML creation
Issue #427 - fix requireDoubleEntry field in XML creation
Issue #427 - add "free text details" to question handlebars file
Issue #454 - change geonames API call
Merge branch 'develop' of https://github.com/akvo/akvo-flow into develop
Issue #454 - correct api address genomes

deleted extra '&'
Merge branch 'feature/427' into develop

Conflicts:
	Dashboard/app/js/templates/navSurveys/question-view.handlebars
[#456] Implements /devicenotification endpoint

* Introduces a new kind `DeviceFileJobQueue` that holds the pending
  images per device
* If a `deviceId` on `DeviceFileJobQueue` is `null`, it means that
  applies to *all* devices
[#457] Add property apkS3Path to appengine-web.xml
[#457] Create DeviceApplication entry for new APK version

* when we have a new apk version, this rest API is called with the new version number as parameter.
[#457] Enable /deviceapprest endpoint

* this endpoint refers to DeviceApplicationRestService
[#457] Add autoUpdateApk property to appengine-web

* When autoUpdateApk = true, the server will respond
to requests from the device for the latest ape version.
If it is false, it will just return null.
[#456] Initialize reponse members to avoid null values

* Reuse response object to reply consistent data
* Initialize Response members to avoid `null` values in the response
[#456] Remove trailing white spaces

* No code change
[#456] Adds support for checking an image when ingesting a file

* When saving the `QuestionAnswerStore` entities, we check for `IMAGE`
  type entities, and add a task to a queue for each entry
* Adss a *stubb* ImageCheckServlet that performs the check
[#458] Add uuid to surveyInstance when created at import

* When a surveyInstance is created through an import, we
add a uuid.
[#456] - Implement image check task

* Implements a way of checking up to 3 times the existence of an image
  in the remote location defined by `photo_url_root` system property
* Make public the connection timeout to be reused `TaskServlet`
* Move the parameter names to constants
[#456] - Adds info logging when rescheduling a check
[#456] Build a response proper response for the device notification

* The current JSON library we're using can't handle the serialization
  properly
* When the resp contains data it generates somethin like:
  {"missingUnknown":[],
   "missingFiles":[{"bytes":[{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{}],
   "empty":false}]}