Fluent API support

[v-kravets]

There are few pull requests to add Fluent API support #533 #727 #1002 from 3 different people that willing to support the project. But no one created an issue to generalize them as this one.

This addition would allow to support SOLID principles for entities that currently need to be decorated by attributes and allow to have separation of implementation details from domain model in terms of DDD.

If you need Fluent API support in the current project - please like this issue, so that it would be easy to count interested people.

[lancecontreras]

Trying to build out of @roygoode's fork to allow fluent API. Is there anyone almost close to making that work? I'm willing to collaborate. My project will benefit a lot from that.

Pull request created #1220

[riddlemd]

Is this dead? Basically a show stopper for me using sqlite-net atm... =*(