Resolves #302

Fix case insensitive commands forcing parameters to return lowercase

Nickname changes/role changes are no longer sent over PRESENCE_UPDATE, making it obsolete to check for changes there.

Fixed async method

CheckPermissions was not set to async so await would not work.

Fixed Install -> commands.LoadAssembly

await commands.LoadAssembly(Assembly.GetCurrentAssembly(), map);
->
await commands.AddModulesAsync(Assembly.GetEntryAssembly());

Fixed HandleCommand Error message

if (!result.IsSuccess)
    await msg.Channel.SendMessageAsync(result.ErrorReason);
}
msg -> context

*facepalm*

EmbedBuilder.WithImageUrl() now uses the value passed

Add TimeSpan TypeReader

Adds Timestamps to embeds, and removes Image and Thumbnail-Builders

Add configuration option for case insensitive commands

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

Close the WebSocket when disconnecting

Throw an exception when creating a Color with an invalid float value

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 prevents a 400 when sending a malformed color to Discord.