Notify that a default adapter type has been selected

This will notify that in the absence of custom adapter
a default has been selected.
Test registerEnumTransform on Adapter class instead of adapter instance

As the registerTransform is call on the class, the registerEnumTransform should operate on the class as well
Allow call to registerEnumTransform on Adapter class, fix #786
Fixed non camelCase variable
Extract record array responsibility

This extracts record array management responsibility out of DS.Store
and moves it into a new DS.RecordArrayManager.
remove transaction-level book-keeping
Merge pull request #895 from ghempton/simplify-transactions

Simplify Transaction Implementation
Merge pull request #787 from bobbus/fix-register-enum-transform-on-class

Allow calling registerEnumTransform on the Adapter class
use a transaction to save records
Merge pull request #690 from trek/notify-that-a-default-adapter-is-used

Notify that a default adapter type has been selected
Merge pull request #902 from tchak/schedule-save

use a transaction to save records