Handle operation with depth > 1

[stombre]

Introduction

Currently the ORM support direct link A ref B A.linkedWith B !!

This issue is an idea to introduce more depth; A ref B B ref C A linkedWith C

Todo

• [ ] Resolve deep relation between concept (in Relation class ? Dummy vs A* / Djistra ?)
• [ ] Make linkedWith work with deep reference
• [ ] Way to overload behavior when resolving complex reference (for handling join operator in SQL eventually)