* Added the component and ratingarea fields and implemented it throughout
the rating API as mandatory fields
* Cleanup rating indexes
* Upgrade forum/data/glossary ratings
* Moved the logic in the render_rating method to methods of the rating object.
* Added new callback for checking ratingareas
* Cleaned comments here and there
* Mark the xxx_get_participants methods as deprecated
* Refactor rate_ajax and ratingsuser_can_view_aggregate methods
* Cleaned up rating/index.php to use html_table object and moved inline styles to CSS.
* Added missing properties of the rating object that were being set throughout the rating
API.
These are David's changes of Mark's code that replace the
plan/tasks/steps infrastructure with a bit simpler one. The changes will
be described in the next commit that will actually finish the
conversion.
TODO: refactor backup/converter/moodle1/stepslib.php into conversion
handlers.
* Several base_converter methods made protected when there was no obvious
reason why they should be public (subject of eventual change still).
* The conversion chain now constructed in advance before any converter
class is instantiated, using Dijkstra's algorithm.
