Document `findOrCreate.merge`, add a change log, fix some display issues.
Fix `add`, `merge` and `remove` options on coll.add or relation.set. Ref #224
Add docs for `RelationalModel.set`
Only modify `this.related` through `setRelated`; restore an accidentally commented-out test.
Docs: use more logical link names for attributes of `RelationalModel.relations`
Couple of small simplifications
Upgrade underscore to 1.4.4; replace `detect` with `findWhere`.
keyIds should not contain null-entries

- this is especially relevant when new models with null-ids are matched
against keyIds and a false-match (null === null) is found
added test-case for supplied pull-request (keyIds should not contain
null-entries)
ignoring 'falsy' keyContents except 0
Collection._prepareModel: only `_validate` new models
Big rework of `change:` event. Removes separate `update:` event. Fixes #276.
Fix wrong info on `Backbone.store`, add `autoFetch` to the sidebar
adding only non-falsy itemIds to keyIds array
fixed bug introduced with 963296feca2ef585765cd812ad5747c97bc05727

- valueSub has to be an array for Collections and object for Models
Merge pull request #280 from ClemensSchneider/toJSON_fix

Fixed bug with `valueSub` in `toJSON` introduced by 963296feca2ef585765cd812ad5747c97bc05727
Merge pull request #277 from ClemensSchneider/keyIds_should_not_contain_null_entries

keyIds should not contain null-entries
Add a testcase for #280; replace `.bind` with `.on` in the tests.
Add some comments for `change:<key>`, whitespace fixes
test showing change events shouldn't fire too often