Organized and fixed unwind tests

The unwind tests weren't organized, and when they failed they failed
badly.
- Moved the bug#1509 and bug#1515 tests to their generating function
sections.
- Moved the basic functionality tests of break, continue and throw to
their
corresponding handler functions.
- Added missing break and continue tests to loops that didn't have them.
- Changed some loop tests so they didn't succeed by accident.
- Made sure the loop unwind tests wouldn't go infinite if they fail.
The forever tests will still be infinite loops if they fail.
- Tests for while bug#1519 for both true and false fallback conditions.
- Got rid of some duplicate tests.
- Added word initialization tests for use.