Refactored binding & elution into a connected model

The binding & elution models follow a similar pattern
- they have a number of inputs that are promises;
- they have outputs that are of a particular model;
- they create the same number of outputs are inputs;
- they print barcodes for the created outputs;
- they need to lookup inputs by barcode;
- they need to lookup outputs by barcode.

The 'connected' model refactors the common behaviour into a single
location, ensuring that this is consistent between the two.
Move connected configuration into pipeline configuration
Refactored binding & elution presenter setup

Sub presenter setup is down to the model, not the presenter now.
Move dealing with finding inputs/outputs into connected model
Use owner from model, rather than passing presenter
Remove some unused members
Merge pull request #62 from mattdenner/refactoring_to_connected_model

Refactoring to connected model