Merge pull request #99 from denibertovic/develop

verification emails and make groups and accounts reachable from tenants
Adding info about new feature.
some prospector cleanup
added memcached cache backend
add doc strings for RedisStore
fix tests failing for py <= 3.2
Merge pull request #100 from denibertovic/memcached

Add memcached cache backend
Adding changelog info.
Adding release date.
Version bump.
Updating GA.
Fixing UA.
Add optional account store for password reset

When creating a password reset token the user can now specify an account
store that hold the desired account. If no account store is specified
the Backend uses the default account store to look for the account.

This is useful if one has multiple account store for an application
that hold the same email address.