Adding FIELD_ID to QAModel
Fixing links in README.
Fixing more README links.
Remove duplicate code from merge.
Adding spelling and stylistic fixes.
Initial version and tests for NetworkDataManager writing.
Adding implementation and test of NetworkDataManager write.
Adding serialization to model GsonTypeAdapters.
Fixing serialization for AnswerItem, CommentItem, and UpvoteItem.
Adding mutex locks to NetworkDataManager queries.
Adding multiple item save test.