Ported RedUNIT specific Sqlite tests to PHPUnit

![coverage-sqlite](https://f.cloud.github.com/assets/227395/1708919/1dd6ce5e-6116-11e3-9428-6e6d5e008b84.png)

Some tests were marked as skipped. I need some feedback about these tests. They are not passing due to an error related to `$bean->sharedEntity`. Need some help to understanding why these errors are happening. Are RedUNIT related tests passing?

Would be great if somebody with more RedBean Karma review it very carefully. Coverage is automatically generated at `build/logs/coverage/index.html`.


TODO:

- update doc blocks. I left the old doc blocks for historical reasons.
- some tests are too long, should we split these tests into smaller ones?