Changes

Summary

1. Add IGuildChannelContainer and getChannelById(Class, id) (#1949) (commit: c3c1e2b) (details)

Commit c3c1e2b24ae686a7a438b4ef1806cacb1c1df9a9 by noreply Add IGuildChannelContainer and getChannelById(Class, id) (#1949) (commit: c3c1e2b)
	src/main/java/net/dv8tion/jda/api/sharding/ShardManager.java (diff)
	src/main/java/net/dv8tion/jda/api/entities/channel/IGuildChannelContainer.java
	src/main/java/net/dv8tion/jda/api/JDA.java (diff)
	src/main/java/net/dv8tion/jda/api/entities/Category.java (diff)
	src/main/java/net/dv8tion/jda/api/entities/Guild.java (diff)
	src/main/java/net/dv8tion/jda/api/entities/ChannelType.java (diff)