use new Em.Map function signatures
update testem
polyfill Ember.Map behavior
re enable beta and canary channel builds
update comments for map.js
use a for loop for ie compat and performance
don't use call, instead invoke the super function by aliasing it
Always remove the inverse record (if exists) from a belongsTo relationship
fixes #2331
Fix typo in DS.Model.save in-code documetation
pass ids through encodeURIComponent when turning them into urls
Update build command, plus minor text adjustments
a bit verbose, but lets ensure we don’t deoptimize these functions in some runtimes.

* passing arguments object to another function (other then via apply) deoptimizes function body
* materializing the arguments object via splice deoptimizes the function body
some failing async/sync HM -> BT relationship tests
added note about coalescing and custom URLs
Temporary fix for #2344 rollback after delete for recordArrays

This is a temporary fix, it's clear this code needs to be refactored.
Moreover I am not sure that removing deleted records from recordArrays
before they are deleted is a correct design decision.
warn instead of throw when resolving keys to model

Before this commit, if you had a payload like:

```javascript
{
  “posts”: []
}
```

But didn’t have a “post” model defined, Ember
Data would blow up. As discussed in the data
team meeting, we decided to warn if the model
could not be resolved. In this spirit,
Ember Data just doesn’t process what it doesn’t
understand, but can still provide you with a
better debugging message to give you hints on
what your payload should look like.

fixes GH-2337
Rollback after delete record failure

failing test for #2344
Add missing type information to the API docs.
update ember-local version
beta.11 changelog and package.json updates