Adds integration tests concerning '- collection'
Bind "- collection" to change events. Fixes #77

Makes tests pass

Refactor the fix
Cleanup collection test, rm delegation tests

Delegation is better served with existing unit tests.
fix specs for newer version of jsdom
Allow belongs to to be nullified
Give property formatters access to their model instance
Merge pull request #78 from chreekat/bound-collections

Bound collections - fixes #77
Merge pull request #80 from Burgestrand/formatter_context

Give property formatters access to their model instance
lay some groundwork
Don't call get or set in tests
Basics of rewriting properties thing
Define dependency cache on object
Fix model for new properties
Fix formatting
Fix remaining tests
Move association stuff into model where it belongs
Don't put events in properties
Move collection to model
Remove properties
restructure defineProperty spec