- Modified measures functions, to return dataframes with ids as row.names (instead of just a vector of values)
- Changed formula for relationSimilarity.

* measures.R: Modified functions, so they return a dataframe including an identifier for the values (instead of
only the values). To avoid errors caused by not sorting all values. (numSentences,numAnnotations, agreement, workerAgreement,
     - On relationSimilarity: changed formula for calculating the probability.
     P(A | B) = P(A ∩ B) / P(B) instead of P(A | B ) = P(A ∩ B) * P(A) / P(B).
     - Also, transposed the matrix (it is easy to read the values this way).
     - Added Worker-Sentence score: functions workerSentenceCosTAble and workerSentenceScoreTable

* simplify.R:
  - Added getSentenceAnnotations: to obtain a data frame with the individual annotations of the workers.
  - Added getSentenceAnnotators: returns the worker_ids of workers who have annotated the sentece passed as parameter (unit_id).
  - Added zeroDiagonal: sets the diagonal of a data frame to zero (for the metrics of similarity and ambiguity, the diagonal is not useful, and making it 0 ease the calculations).

* workerMetris.R:
  - Modified dataframe creation (now using the functions from measures.R now including the identifiers, instead of only the values).