print of anosim adapted to the new permute API

No more stores 'strata', but 'control' and uses howHead() to show
its result.

It seems that getPermuteMatrix(..., strata=<name>) does not save the
name of the 'strata', but howHead() just prints "Blocks: strata".
adapt envfit printing to the new permute API: no more strata
mantel printing to the new permute API: no more strata
mrpp printing to the new permute API: no more strata
adonis adds howHead() to the heading of the anova table

The permutation information is printed similarly as in
anova.cca.
remove dangling '.' from the output
mso adds "control" attribute to the "vario" item and howHead() shows it
Add empty line between results and permutation details
simper adds "control" attribute for permutations and summary prints it
CCorA returns permute  "control" and print uses howHead() to show it
Document cases when a function returns a "control" item

Some functions return "control" *attributes* with some of their
items: this is not (yet?) documented.
permutest.betadisper also uses howHead() to show permutations
Merge pull request #39 from jarioksa/adapt-print-to-permute-pkg

Adapt print to permute pkg