poolaccum uses permute API (not yet documented)

Function is not made parallel ready, but it uses permute API.
The permute "control" is returned as an attribute, but not
printed or used in any way.
Wait till number of permutations is evaluated before you use it
estaccumR uses permute API and is parallel ready
parallel processing in estaccumR
Document the use of permute API and parallel processing
specaccum uses permute API
renyiaccum uses permute API
tsallisaccum uses permute API
fix slack coding
Return "control" attribute when permute API was used
Merge pull request #91 from jarioksa/accum-permute-api

Use permute API in diversity accumulation models