First batch of empty classes to fill
Move classes around, starting reorganization, boilerplate fill
Start better hierarchising classes
Move some functionality of db.Question to separate classes
Continue great refactor: working on storage backend

Storing to database is greatly simplified: we only store in database
elements for which we need SQL-style query (typically probes and
locationPoints, where we want to be able to get all pending probes, or
finished probes, or collecting locationPoints). But, we only store in
SQL fields what we need to search. The rest goes in a string containing
the JSON representation of the object.

Second, we will also do something similar for everything stored in
sharedPreferences: instead of storing individual values, we'll directly
store the objects as JSON and reload them on app startup. That way we
don't need to write all the getters and setters double (one for the
original class and one for the storage wrapper).
Revert previous deletions in ParametersStorage
Do proper revert of ParametersStorage
Fix probeService
Fix repercussions of fixing ProbeService
PollService is now ProbeService
Further mega-refactoring: building sequences is done

Next steps are:
* reworking the parameter storage layer to accept future grammar v3
* finish implementing all the background classes with a lesser grammar
  v3
* rework the views layer to work with new background classes
* augment grammar v3 to accept multi-page questions and conditionals
Merge branch 'develop' into feature/issue-117-question-sequence-builder
Merge branch 'develop' into feature/issue-117-question-sequence-builder
Some cleanup of ParametersStorage
db and sequence packages should be good for lesser grammar v3
Minor additions for future
Start generalizing probes to sequences
Finish generalizing probes to sequences
Add status to Page and and adapter getter to Question
Start work on view adapters