Upgraded codebase to new PeerDB version.
Use person document methods for display name and avatar.
Automatic reverse references between annotations and highlights.
Updated PeerDB version.
Merge branch 'master' into new-peerdb
Updated to new version from current master.
Not needed anymore.
Added migrations. Fixes #291
Updated to new PeerDB version.
Revert "Not needed anymore."

This reverts commit 94953326f0092859b343b6c088b5393dc6e08a92.

In fact they are needed because otherwise there is too much time between
last definition and when Meteor.startup is called and PeerDB complains
about delayed documents.
Merge pull request #323 from peerlibrary/new-peerdb

New PeerDB version