add default 'offline' type to unit tests.
test_calendar_today_date.py - Set the time to be only the start of today rather than Jan1 2013
Remove faulty/redundant tearDown from test_settings_passcode
Update destructive warning to explicitly mention the microSD
Git issue #989 - switch the 'online' manifest tag for marketplace_connectivity_test to be online=true.
This can be reverted when marketplace-dev is installed on Engineering builds by default.