created migration for splitting up the offering_learner table.
bumped migration number.
bumped migration number.
removed triggers on offering_learner and added replacements on offering_x_learner and offering_x_group.
remved offering_learner from schema definition, added tables offering_x_learner and offering_x_group instead.
changed utf8 collation for newly created tables.
updated stored procedure nuke_offering() according to recent schema changes.
updated queries to reflect schema changes.
updated query in deleteGroupWithGroupId() to reflect schema changes.
updated query in isAssociatedWithLockedAndArchivedCourses() to reflect schema changes.
updated internals of deleteOffering() to reflect schema changes.
renamed method getLearnerGroupsForOffering() to getLearnersAndLearnerGroupsForOffering() and implemented separate methods for individually querying groups and learners by offering id.
freed query results. death to array_push()
refactored internals of getLearnerGroupsForOffering() and getLearnersForOFfering() to reduce the number of required roundtrips to the db.
updated method docblocks.
split off code for retrieving learner groups by offering into its own method. adjusted calling code accordingly.
improved method docblocks.
renamed offering_group to offering_x_group in _getLearnerGroupIds().
renamed offering_group to offering_x_group in _saveLearnerGroupAssociations().
removed blank lines.