Not pretty, but it works.

Resolves #469

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

Add Roles property to SocketGuildUser

Typo

Fixed couple non-default arguments in REST messages

Fix ParameterInfo.Type sometimes being null

there's a few different ways to select a user's roles from their role IDs, and this one seems to be the most efficient.

doesn't seem like there's any reason this shouldn't be included.

never overestimate the end user

this should be handled by #520

Add BeforeExecute/AfterExecute methods to ModuleBase