Merge pull request #10 from petiteargen/master

Small fixes :)
Changed from simulated inventory to real received inventory
Changed default initialization fault for shelf inventories
Added registration/deregistration of services offered by shelves (enables multiple Order Picker -> Shelf conversations)
Clean-up: Fixed shelf->picker conversation print outs
Added the complete behavior of the Simulated Picker to the Real Picker.

Current behaviour: The Picker already selects the best shelf and uses this pose to select a robot.
Added methods to ShelfAgent for register and deregister of services.
Added control sequence to manage available and busy shelfs:
1. A shelf that cannot fulfill an order immediately reregisters.
2. Once a shelf is selected, the Picker ask the rest to reregister, and they do.
V.5.1.N.00.B. Return behaviour implemented in Robot Agent. Now, the robot simulates the returning
of the shelf to its original position. TODO: re-register the shelf selected once the robot returns
the shelf.
V.5.2.N.00.B. Log of the process for a test run. Color-coding to easy-readability of the communication
between agents.
Added comment for Nico
Merge pull request #6 from dieg0-/master

Merging