Discord-py

* Voice support: discordrb can now connect to voice using `bot.voice_connect` and do the following things:
* Play files and URLs using `VoiceBot.play_file`
* Play arbitrary streams using `VoiceBot.play_io`
* Set the volume of future playbacks using `VoiceBot.volume=`
* Pause and resume playback (`VoiceBot.pause` and `VoiceBot.continue`)
* Authentication tokens are now cached and no login request will be made if a cached token is found. This is mostly to reduce strain on Discord's servers.

Bugfixes
* Some latent ID casting errors were fixed - those would probably never have been noticed anyway, but they're fixed now.
* `Bot.parse_mention` now works, it didn't work at all previously

* The `User` class now has the methods `add_role` and `remove_role` which add a role to a user and remove it, respectively.
* All data classes now have a useful `==` implementation.
* **The `Game` class and all references to it were removed**. Games are now only identified by their name.

Bugfixes
* When a role is deleted, the ID is now obtained correctly. (30)

* Presence event handling is now divided into two separate events; `PresenceEvent` to handle online/offline/idle statuses and `PlayingEvent` to handle users playing games.
* The `user` property of `MessageEvent` is now automatically resolved to the cached user, so you can modify roles instantly without having to resolve it yourself.
* `Message` now has a useful `to_s` method that just returns the content.

Bugfixes
* The `TypingEvent` `user` property is now initialized correctly (29, thanks purintai)

*Bugfix-only release.*

Bugfixes
* The `user` and `server` properties of `PresenceEvent` are now initialized correctly.

* The `Bot.game` property can now be set to an arbitrary string.
* Discord mentions are handled in the old way again, after Discord reverted an API change.

* Add `Server.leave_server` as an alias for `delete_server`
* Use the new Discord mention format (mentions array). **Reverted in 1.4.5**
* Discord rate limited API calls are now handled correctly - discordrb will try again after the specified time.
* Debug logging is now handled by a separate `Logger` class

Bugfixes
* Message timestamps are now parsed correctly.
* The quickadders for awaits (`User.await`, `Channel.await` etc.) now add the correct awaits.