Add programmatically solving support

A programmatically interface would be a very nice feature in Optaplanner.

I am using Optaplanner currently for optimum search of a black box function with a couple of variables involved and a scoring class. Right now I would like to use it for a new problem but I am forced to reprogram my problem via annotations.
Also a programmatically interface would make it easier to step into evaluation and testing Optaplanner.

For my approach I need mainly following functionality:

• 1) variables with specific range providers
• 2) a scoring interface receiving the current solution offer
• 3) an access to configuration to specify search strategies and its parameters

It would be nice to have an estimation of such an interface involving all changes necessary, so I might have a chance to step into contribution.