Add ways to show if someone is following the user

[pfrazee]

Currently there's no efficient way to find out if a user follows you.

Here's what I'd suggest adding:

• Update actor.getProfile, graph.getFollows, and graph.getFollowers to include a boolean indicating if the actor follows you.
• Probably do the same with actor.search and actor.getSuggestions
• Not necessary but might be worth updating graph.getFollows to optionally take a target actor to quickly determine if someone follows a specific actor. Alternatively can add a separate method.

[dholms]

fixed #539