Ignore '.idea' directory (JetBrains IDEs).
Make the 'belongsTo' relation function, when used as a sync getter, return the cached value if available.
In model's 'updateAttributes', save data returned by model's 'toObject()' to make sure setters have been applied (e.g. foreign keys are transformed to ObjectId for mongo).
Merge branch 'updateAttributes_and_foreign_keys'
0.2.0-34001
Undo version change, npm did not like it (why?)!