The old conditionlib.php, which is replaced by the new availability
API, has been deprecated.
* Code which uses the key functions (is_available,
get_full_information) should still work. These now show
deprecated warnings and then pass through to equivalents in the
new API.
* I have created new unit tests for these functions.
* The old language file has been removed (reused strings already
moved with AMOS).
* Most other functions throw exceptions because it was impossible
(due to fundamental API differences) or difficult to reimplement.
* I don't really expect that non-core code (outside unit tests) will
have used any of the other functions.
Credit: original version done by Kirill Astashov of NetSpot (netspot.com.au),
finished and tweaked by sam.
This change adds conditional availability support for sections analagous to
that already available for activities. (Backend, UI, backup/restore.)
In order that this feature does not reduce performance, section cacheing has
also been added using a new course 'sectioncache' field analagous to modinfo.
The new feature integrates with activity availability so that activities
inside sections which are not available are automatically not available
themselves (meaning it works to restrict access).
sam marshall