[FIX] Fix errors using numpy 1.13

[ales-erjavec]

• numpy 1.13 raises an error when applying an negation operator on a boolean array.

------------------- TypeError Exception (in non-GUI thread) -------------------
Traceback (most recent call last):
  File "/Users/aleserjavec/workspace/orange-bio/orangecontrib/bio/widgets3/OWMAPlot.py", line 121, in wrapped
    return func(*args, **kwargs)
  File "/Users/aleserjavec/workspace/orange-bio/orangecontrib/bio/widgets3/OWMAPlot.py", line 394, in run
    progressCallback=lambda val: progressCallback(50 + val / 2))
  File "/Users/aleserjavec/workspace/orange-bio/orangecontrib/bio/utils/expression.py", line 872, in MA_zscore
    z_scores._mask = - numpy.isfinite(z_scores)
TypeError: The numpy boolean negative, the `-` operator, is not supported, use the `~` operator or the logical_not function instead.

• numpy 1.13 raises an error on indexing with non integer scalar array.

  ----------------------------- TypeError Exception -----------------------------
  Traceback (most recent call last):
  File "/Users/aleserjavec/workspace/orange-bio/orangecontrib/bio/widgets3/OWFeatureSelection.py", line 1169, in select_p_best
  self.histogram.setUpper(cut)
  File "/Users/aleserjavec/workspace/orange-bio/orangecontrib/bio/widgets3/OWFeatureSelection.py", line 342, in setUpper
  self.__update_tails()
  File "/Users/aleserjavec/workspace/orange-bio/orangecontrib/bio/widgets3/OWFeatureSelection.py", line 432, in __update_tails
  datahigh = histogram_cut(hist, edges, self.__max, edges[-1])
  File "/Users/aleserjavec/workspace/orange-bio/orangecontrib/bio/widgets3/OWFeatureSelection.py", line 488, in histogram_cut
  cbins = bins[lowidx: highidx]
  TypeError: only integer scalar arrays can be converted to a scalar index