Merge pull request #49 from gavinsimpson/master

fix a bug in calculation of p value in group pairwise permutation test
nestedness indices return named statistics
Update tests/Examples
simulate.[rda,cca,capscale] only work with constrained ordination

Earlier they gave results, but these were wrong because fitted
component did not exist, and wrong component was used for them.
Now check and stop informatively.
remove scoverage()

If this function is resurrected, it should be documented independently
and not with the decostand.
Merge pull request #50 from jarioksa/revert-scoverage

remove scoverage()
update tests/Examples
downplay scores.hclust: combine help into reorder.hclust

I considered dropping scores.hclust as it is pretty complicated
to use: you need to know how the internal nodes are ordered. However,
I have some uses for this small function and still let it be here
(but it still at vulnerable status).
update tests/Examples