divided LabeledEvidence in 2: EvidenceCandidate and EvidenceLabel
added restriction to models, reconstructed migration
changed way to retrieve evidences for a relation, now needs a judge
changed get_labeled_evidences occurrences, fixed tests
added factory for evidence candidate
reverted the need of providing "judge" when asking segment.get_evidences. Not clear why was that needed
fixing hover UI
Defining Form models now for EvidenceLabels instead for LabeledRelationEvidences
basic changes for allowing LabelBySegment work with new models
adapted navigation on labels and segments
fixed tests for segment and document navigation
fixed django navigation view
basic changes now to allow label-by-document to barely work
get next to label takes the judge as argument
unifying judge-name-from-request on views
get next segment to label picks first my own nones, later the smae old logic is applied
making succeed test of get next document to label
fixing some tests that were using wrong call parameters to methods
fixing some tests that were using wrong call parameters to methods
data migration and model migrations added