AudioApplication is a required argument

Thanks @MinnDevelopment for his awesome work on
the JDA guide that had no influence here at all.

🥄 better docs soon come

ConnectAsync -> StartAsync

This should resolve a plethora of relates issues, including user downloading not working (#542), possibly #531

A null conditional operator was required at line 70 to avoid a nullref.

Conflicts:
	src/Discord.Net.WebSocket/DiscordSocketClient.cs

Check that messages older than two weeks are not passed to bulk delete

Not pretty, but it works.

Connection/API lag could cause messages right on the edge of 14 weeks to fail on Discord's end when they pass our checks.

Resolves #469

This resolves #477

Replace IUser.AvatarUrl with IUser#GetAvatarUrl(size)

This is to support the new user image endpoint, which provides a parameter for image resizing.

Conflicts:
	docs/guides/samples/dependency_module.cs
	src/Discord.Net.Commands/Utilities/ReflectionUtils.cs

Enhance Dependency Injection

Conflicts:
	docs/guides/samples/logging.cs
Update logging.cs

Update home page on docs

Update doc samples

Update docs' status sample

Add Roles property to SocketGuildUser