adonis accepts permutations=0

This allows evaluation of the statistic only and allows embedding
adonis in, say, oecosimu.
anosim acceptes permutations = 0
mrpp works with permutations = 0

mrpp is multiresponse *permutation* procedure: it may not produce any
sensible result without permutation, but what am I to say what people
should do.
print no. of permutations also with zero permutations in mrpp
Merge pull request #38 from jarioksa/zero-permutations-should-be-accepted

Zero permutations should be accepted