Remove changelog entry for reverted LenientCookie feature.
Update release constraints:

- Depend on Py3k compatible versions of zope.contenttype/zope.interface.

- Depend on non-alpha versions of zope.i18n/zope.security.
Nest into Github.

Also, avoid ResourceWarnings on Py3k.
Gardening:  next release is 4.0.0.
Prep 4.0.0 release.
svb