Sample Preparation workflows.

Preparation workflow happens at "receive" transition

Field is visible in AR add, and AR and Sample views

Conflicts:
	bika/lims/content/batch.py
Sample Prep Workflows

The automatic transition to sampleprep is now invoked at "recieve" via
automatic dcworkflow transition.

Remove test sampleprep workflows: added sampleprep_simple.csv, a
single-step sampleprep workflow.

Add sample_prep state to analysisrequest visible= to control which
fields are visible or editable in this state.
LIMS-1404

LIMS-1378

Conflicts:
	bika/lims/content/batch.py
Fix display or hiding of Batch/Client fields in different contexts

widget visibility settings for Client and Batch field in the ar_add form
Fix error dereferencing empty references.
matrix.SampleMatrix runtime error in Sample view.