Currently, commands are case-sensitive. This PR allows for commands to be case insensitive (which is now the default option).

Conflicts:
	src/Discord.Net.Commands/CommandService.cs

For a command to use the DefaultRunMode, it must now have it's RunMode set to RunMode.Default (this is the default value on CommandAttribute now).

This adds an (optional) CommandServiceConfig, as well as a DefaultRunMode for commands.

This resolves #368 (for commands where a RunMode is not explicitly specified, a custom default value should be used)

This is a breaking change.

Adds a precondition that requires the bot has a specified permission (Resolves #211).

Renames RequirePermission to RequireUserPermission.

This precondition will require that the invoker of the command is the owner of the bot.

This should Fix #262

This probably isn't all of them. This is what I get for copy+pasting code.

In theory this should just work, more testing is needed though

Values in ImmutableDictionaries were strings rather than enumType

Right now commands require a module before they can be created;
I'm looking to remove this in the future.

Move DI stuff around to support scoped DI

Prevents an NRE when creating a CommandContext from a message in an IDMChannel

TypeInfo.BaseType will likely return the same Type if all modules derive from
ModuleBase or some common subclass of it. Making it appear as if only one module
is registered.

Changed to TypeInfo.AsType for expected behavior.

Exclude abstract types from being loaded as modules.