* docs/project.org: TODO updates (feedback from M Rieppel)
* .gitignore: allow for multiple testing dirs
* examples/config.py: better documentation for gradedb_file var
* schoolutils/grading/ui.py: first pass at new SimpleUI.initial_database_connection
* schoolutils/grading/db.py: connect(): more robust connection
  - test that database has correct tables, is not read-only, etc.
* schoolutils/grading/ui.py: cleaner implementation of SimpleUI.initial_database_setup
* schoolutils/grading/ui.py: change_database: catch db.ConnectionError
* schoolutils/grading/ui.py: BUGFIX: main_loop: call commit() only if db_connection exists
* schoolutils/grading/ui.py: use print_function for python3 compatibility
schoolutils{config/__init__.py, grading/ui.py}: use dict.items(), not iteritems()
* schoolutils/grading/ui.py: rename raw_input to input for python 3 support
* schoolutils/reporting/reports.py: rename cStringIO to io; pass unicode to StringIO.write
* docs/project.org: notes on Py3 support status
* schoolutils/reporting/reports.py: use list comp instead of filter()
* docs/project.org: more notes on Py3 support
* docs/project.org: TODO updates based on feedback
* schoolutils/grading/calculator_helpers.py: map, filter updates for python 3 support
* schoolutils/grading/ui.py: py 3 support: explicit encoding when writing grade report
* schoolutils/grading/ui.py: py 3 support: map, filter fixes
* schoolutils/grading/ui.py: fix indentation issue (thanks, pylint)