Expose config.Dynamic

[nirinchev]

Fixes #778

TODO:

• Tests

[fealebenpae]

I think just exposing Dynamic has limited usefulness - I imagine users would need a way to provide a RealmSchema that they have constructed manually.

What’s the use case for just Dynamic?

[nirinchev]

There are two cases that I have come across already:

• Writing a .NET browser/studio app
• Compacting a large Realm

I agree that ultimately, exposing a mechanism to provide the schema is what we should do, but until that's done, it's a cheap enhancement to unblock some people.

[listepo-alterpost]

@nirinchev hi, when this will be release?

[Zhuinden]

@listepo-alterpost 2.2.0 (2017-03-22)