[#504] Fix missing question settings

Correcting the copy of survey questions from one instance to another
where some settings were missing
[#504] Take into account "null" string for Boolean fields

In cases where a boolean value is not set in json response, i.e. "null" string is
returned as response, ensure that corresponding field is also set to null
[#497] Cleanup GWT portal code
Merge pull request #532 from akvo/feature/504

[#504] Fix for missing data when transferring surveys
[#497] GWT survey entry client code cleanup
[#497] GWT code servlet classes cleanup
[#497] GWT Code cleanup removing URL mappings
[#497] GWT client code cleanup
[#497] GWT code cleanup
[#497] GWT code cleanup + TestHarnessServlet class cleanup
Merge pull request #535 from akvo/feature/497

[#497] GWT code cleanup
[#497] GWT cleanup Dto's + Config + build file
[#497] GWT code cleanup
[#497] Delete GWT ant build task
Merge pull request #536 from akvo/feature/497

[#497] GWT code cleanup
[#497] GWT code cleanup

Spreadsheet processing code related to spreadsheets
containing access point information
[#497] GWT code cleanup

Cleanup AccessPointDto and related code
[#497] GWT code cleanup

Cleanup AccessPointSummaryDto and related servlet classes
Merge pull request #540 from akvo/feature/497

[#497] GWT code cleanup
[#320] NO_IMEI should be treated as null

On WiFi only mobile devices (no SIM, no imei) the dashboard was storing
"NO_IMEI" as value, and that makes all this devices to be handled as the
same.

If we try to get a device by `imei` and is "NO_IMEI" we immediatly
return `null`, and the related code needs to search by `phoneNumber`.

`phoneNumber` property stores either the actual mobile phone number or
the MAC address of the device.