Issue #32 - Handle null phoneNumber and imei cases
Issue #32 - Handle no network scenario

* Display network error notification/toast
Issue #32 - Avoid implicit creation of records

* Only allow explicit creation of records ("New Record")
* Create the records in SurveyedLocalesActivity, the return the ID
Issue #32 - Reuse adapter views
Issue #32 - Pass locale and group id
Issue #32 - Implement last instance getter

* Given a locale and survey IDs, get the last
surveyInstance matching that criteria
Issue #32 - Make sure response is not null
Issue #32 - Implement pre-fill answers option

* Display option, if applies
* Load last survey instance, and its answers
* Save the state with new answers