Includes:

• constants refactoring
• new half-finished geenrator
• reworked db table init
• support for $CFG->debug = -1
• functional DB tests
• fixed $DB->get_indexes() to not throw exceptions when table does not exist
• fix handling of user passwords in test db
• add debug info to exception messages
• removed unnecessary PHP debug errors from mathslib
• fixed @error suppression in get_string
• fixed PHPUnit error handler setup
• added timezone info to default install

====================

remaining tests:

• grade tests seem to be kind of broken from MDL-24330, it might be best to revert it completely (do not ask me why it passes at present, I tried conversion and failed pretty badly)
• completionlib - using mocks heavily
• /question/* (Tim?)
• webservices - seems to do nothing
• /mod/data/simpletest/* needs to be rewritten to use data generator instead of stored CSV records that include links ids

TODO:

• discuss problem in navigationlib_test.php method test_find_expandable()