Various small fixes for working with Olingo OData v2 server

When we tried to use Breeze with Olingo as backend OData provider... we faced with series of issues (some times with specific behavior of Olingo and sometimes due to issues in breeze odata adapter). 

This pull request is a attempt to contribute back those changes to breeze community.

I have tried not to disturb any of the existing code. I do not know breeze enough to confidently say that all these changes will work perfect for you. Also am being java developer, I do not have running environment to see breeze development. Hence you may need to edit some of these changes before merging .. but their core value should become helpful to you and others in the community.