Generic Objects/JSON support

[grecinto]

One of V3 features is support for map[string]interface object. And the companion Comparer for such.

This feature will allow fully dynamic data structure support. Not requiring recompilation or compile/build time bind as what happens in Golang generics.

Also, it will enable a full, cross language dynamic data structure integration. (JSON)

[grecinto]

This was implemented, see "..sop/jsondb" package.