Add outline of new database schema and TODO list to implement it

Related #667
Related #484
Related #671
Add database.py tests and refactoring

- Remove test methods that only check function return types

- Create resources folder for common test data like test rss feeds

- Fix database.py query bugs

- Add database folder for database related tests

- Refactor common database fixtures into the database conftest file

- Refactor comments in database.py

- Refactor queries in database.py to have better style and sanitization

- Add comments and examples of the presentation time stamps

- Remove unused functions from database.py

- Add httpretty mock tests for database.py

- Add a database schema upgrade test

- Add tests that check multiple scenarios of each method in database.py

- Replace string % operators with calls to format for nonlog string formatting

- Remove several try/finally statements and replaced them with 'with's

- Fix an exception logging statement which referred to an out of scope value

- Add failure and presentation equality and inequality comparison functions

- Add example of parameterized test with fixtures

- Add fixtures based on summer camp 2010 and 2011 stored data

Related #484
Related #667
Related #670
Updated tests to reflect empty string default value for presentation field
Updated the newer csv Presentation constructor to use the QTime format instead of the modified isodate format.
made the csv importer use the hh:mm ap format for the presentation StartTime and EndTime. Added two remarks in the Presentation docstring on the format of Presentation.Date and Presentation.StartTime in the database and in csv files.