Merge branch 'develop'
Merge branch 'release/1.6.12'
[#487] Add survey group columns to survey header response

* Add survey group id and name, plus constants false (monitored) and
null registration survey id
* Include this info in both survey header response and surveys-for-phone
response
[#487] Remove whitespace
Merge pull request #489 from akvo/feature/apk_comp

[#487] Add survey group columns to survey header response
[#490] Delete DevicesjobQueue entities

* Query and delete any DevicesjobQueue associated with the assignment
[#490] Remove whitespace
Merge pull request #491 from akvo/feature/issue490

[#490] Delete DevicesjobQueue entities
[#492] Release Notes v1.6.13
[#492] Fix typo in release notes
Merge branch 'release/1.6.13'
Merge branch 'master' into develop
[#494] Make translatable strings

* Removes hardcoded English strings
[#494] Adds french translation, plus "devices not in a group"
[#494] Small grammar fix
Merge pull request #495 from akvo/feature/494

[#494] Make translatable strings
Merge branch 'develop' into feature/363-2