[#692] Code clean up

* Removes unused imports, variables
* Formats some `if` expressions
[#697] Select first question column index

* Avoid side effects on `firstQuestionCol` variable
Merge pull request #701 from akvo/issue/697

[#697] Select first question column index
Merge pull request #693 from akvo/issue/692

[#692] Code clean up
[#690] Merge branch 'develop' into issue/690