WIP Refactoring
Revisionable testing now uses RevisionableThing class, Programme specific stuff is now in Programme
Refactored Revisionable populate()
Merge branch 'master' of github.com:unikent/programmes-plant into develop
Merge branch 'develop' of github.com:unikent/programmes-plant into develop
Merge branch 'enhancement/refactored_tests' of github.com:unikent/programmes-plant into develop

Conflicts:
	application/tests/models/programme.test.php
	application/tests/models/revisionable.test.php