Refactor serializeAttribute out of serialize
Merge pull request #1208 from daliwali/master

check if record exists for asynchronous belongsTo
Merge pull request #1204 from bradleypriest/serializeAttribute

Refactor serializeAttribute out of serialize
Accepted relationship transition; thx jagthedrummer

Closes #1205
Pass a string, not the type, to buildURL

This will make subclassing, munging the type, and calling super work
more sanely.
Reimplemented `rootForType`
Merge pull request #1212 from bradleypriest/rootForType

Reimplemented `rootForType`
amend asynchronous belongsTo fix