changelog:
removed users_id. users_loginId is the primary key. Result of IsAuthorizedUser contained this field. If it is being used in anyway on ipad, it needs to be removed.

SetAnswers now expects a field called answers_id. Presence of this field indicates that we need to update answer in the database and absence of this means we need to insert new row in answers table.

Remember to call SetNewSurvey when user starts a new survey.

Only following info id updated when sending an answer for a question that has been previously answered.
'UPDATE `answers`
             SET `answers_value` = ?, `answers_attachment_path` = ?,
                 `answers_date` = ?, `answers_comment` = ?
             WHERE `answers_id` = ?'

--uploading image for a question after reanswering it in another session on ipad will not delete the previous picture from the file store.