Batchhandler results in an error when doing bulk updates. #760
Description
Short summary (3-5 sentences) describing the issue.
Assemblies affected
AspNet RESTier 1.1.0
Reproduce steps
Any batch request with more then 1 change.
Expected result
Batch request is properly handled.
Actual result
Batch crashes sometimes, depending on how many changes are sent.
Additional details
RestierBatchChangeSetRequestItem defines a dictionary that is used while firing the individual requests async.