mavis doesn't want mavis types on itself

This line was left over from early experimentation but was never
actually used.
Remove activate/1

Thanks to some pointers from Jan Wielemaker, I am now able to discern
which modules want mavis processing and which ones don't.
Remove Name section of docs

SWI-Prolog's online pack listing includes this information, so there's
no need to repeat it.
Bump version