fix for bad relationship change keyname when mutating a belongsTo
Merge pull request #955 from ghempton/relchange-fix

fix for bad relationship change keyname when mutating a belongsTo
added in progress warning
Remove BasicAdapter

So long, old friend. For more, see:
http://emberjs.com/blog/2013/05/03/ember-data-progress-update.html
Merge pull request #960 from kagemusha/in-progress-warning

added in progress warning
remove a trailing , at the last method in the serializer
Merge pull request #961 from christoph-frick/master

fixed a syntax error (at least for some browsers)
Advanced errors handling