Added retrieval functionality to the mysql wrapper
DatabaseHelper now retrieves data using mysql wrapper. Also added ability to create custom queries
Added in memory cache for the mysql paging functionality
Remove unnecessary file storage wrapper command
MySQL migration part 2: Updated retrieval API - raw data
MySQL migration part 2: Updated retrieval API - users
MySQL migration part 2: retrieval API - device inventory
MySQL migration part 2: Updated retrieval API - questionnaire duplicates
MySQL migration part 2: Updated retrieval api - facebook tokens
MySQL migration part 2: Update retrieval API - status (partially)
Merge branch 'devel' into mysql
Fixed bug in mysql wrapper where date queries where not correctly formatted
Fixed deanonymizer function to work with mysql data
Merge branch 'devel' into mysql

Conflicts:
	sensible_data_service/db_access/mysql_wrapper.py
	sensible_data_service/utils/db_wrapper.py
Fixed a bug in mysql wrapper where an exception would be thrown if no where constraints were used
Fixed csv printing for raw data api
Added user to bluetooth address mapping method (as opposed to the already existing bluetooth to user method)
Merge branch 'devel' into mysql
Removed database status info on the status page temporarily.
Timestamps retrieved from the database are returned by the API as seconds from epoch and not datetime objects