Revert "some more work on supporting recursive descriptors properly"

This reverts commit 6cb5b981a8515ecb4c6cf2b293d8b82263b20ad4.
recursive descriptors are a pain in the ass and far too much work to support. Good support for recursive strategies is important, recursive descriptos not really
Merge branch 'master' of github.com:DRMacIver/hypothesis