Resource Generator abstract class

[bkilinc]

Feature Request

Q	A
New Feature	yes
RFC	yes/no
BC Break	yes/no

Summary

Library heavily depends on static ResourceGenerator class. It is nearly impossible to create your own. As strategy methods accepts this type of class. It is possible to extend the class but its constructor requires metadatamap, hydrators, linkgenerator etc. Some of them I don't need and assigning null to them is not possible.

So there should be a an abstract ResourceGenerator class (or interface class) to implement our own.