Improve Model class

[Glavin001]

Rename Node to Model
See http://emberjs.com/api/data/classes/DS.Model.html

[Glavin001]

• keyForAttribute
• keyForRelationship

[Glavin001]

The following should simply forward to the SLAPIManager and pass themselves (self) as the record, when applicable.

• createRecord
• find
• findQuery
• findAll
• findMany
• updateRecord
• deleteRecord

[Glavin001]

• rollback, see http://emberjs.com/api/data/classes/DS.Model.html#method_rollback

[Glavin001]

Here are the headers so far:

- (instancetype) createRecord:(NSDictionary *)properties;
- (PMKPromise *) findById:(SLNid)nid;
- (PMKPromise *) findQuery:(NSDictionary *)query;
- (PMKPromise *) findAll;
- (PMKPromise *) findMany:(NSArray *)ids;
- (instancetype) updateRecord:(NSDictionary *)properties;
- (instancetype) deleteRecord;

[Glavin001]

• setupData, see http://emberjs.com/api/data/classes/DS.Model.html#method_setupData

[Glavin001]

Inspecting Core Data attributes: http://oleb.net/blog/2011/05/inspecting-core-data-attributes/

[Glavin001]

Ideally use something like https://github.com/adamelliot/Inflections to generate the result for the type method.
See https://github.com/Streamlyne/web-app/blob/develop/app/scripts/adapters/streamlyne_adapter.js#L101-L104 for what the web-app does.

[Glavin001]

• save, see https://github.com/emberjs/data/blob/v1.0.0-beta.8/packages/ember-data/lib/system/model/model.js#L883-L910 and https://github.com/emberjs/data/blob/v1.0.0-beta.8/packages/ember-data/lib/system/store.js#L938-L983

[Glavin001]

• all, see http://emberjs.com/api/data/classes/DS.Store.html#method_all

[Glavin001]

• getById, http://emberjs.com/api/data/classes/DS.Store.html#method_getById

[Glavin001]

• filter, in addition to findQuery for an offline method for querying. Also add findQuery:withFilter. Filter is a function boolean-returning block. Should we make it async? findQuery already is. Sure, let's go async. One-Up Ember's implementation. Boo-yeaahhh.