* Add inline replies

* Missed a few things

* Change xml docs, IUserMessage, and other changes

* Missed one when changing

* Fix referencedMessage author

* Feature: Allowed mentions object on msg create (interface breaking)

This change implements the AllowedMentions object for the payload of message creation. By default, the mentions behavior remains unchanged, the message content is parsed for all mentionable entities and they are all notified. If this payload is not null, it will use the content of the allowed_mentions field to determine if a role is notified, or just displayed.

This change is interface breaking. This follows the conventions of keeping RequestOptions as the last argument, but could break some users who specify each of these arguments without using named arguments.

* lint: remove commented-out code

This change removes the commented-out code which was added during testing from the previous commit.

* fix interface break: reorder allowedMentions arg so that it's after options

This change modifies the order of the AllowedMentions argument of SendMessageAsync so that this addition shouldn't be interface breaking. The downside to this change is that it breaks the convention followed by other methods, where the RequestOptions argument is normally last.

* docs: fix typo in allowedMentions arg doc

* fix interface break arg from IRestMessageChannel

* docs: update xmldoc for allowedMentions args

* fix interface breaking arg order for ISocketMessageChannel

* fix mocked classes that weren't updated

* fix: RestDMChannel#SendMessageAsync bug, allowed mentions always null

This change fixes a bug that was introduced while testing changes to the interface of the SendMessageAsync method to try and retain interface compatibility

* docs: update xmldoc for AllowedMentions type

* docs: reword xmldoc of AllowedMentionTypes type

* docs: fix typo

* fix: validate that User/Role flags and UserIds/RoleIds lists are mutually exclusive

This change adds validation to SendMessageAsync which checks that the User flag is mutually exclusive with the list of UserIds, and that the Role flag is also mutually exclusive with the list of RoleIds

* docs: reword summaries for AllowedMentions type

* Add util properties for specifying all or no mentions

Adds read only properties which specify that all mentions or no mentions will notify users. These settings might be more common than others, so this would make them easier to use.

* docs: Resolve PR comments for documentation issues/typos

* Implement CustomStatusGame activity

Adds the CustomStatusGame class, which is the activity corresponding to the custom status feature.

* Remove unused import from Game.cs

Co-authored-by: Chris Johnston <chris@thejohnstons.net>

commit 23f5abba48
Author: Christopher Felegy <foxbot@protonmail.com>
Date:   Thu Dec 20 17:10:21 2018 -0500

    lint: clean up some long lines

commit 4a8a809db0
Author: Chris Johnston <chris@thejohnstons.net>
Date:   Sat Dec 15 00:33:05 2018 -0800

    Explain why CreatorId can be null sometimes

commit 9442e4e635
Author: Chris Johnston <chris@thejohnstons.net>
Date:   Fri Dec 14 23:59:01 2018 -0800

    Add the CreatorId property to GuildEmote implementation

commit e0eb94d44c
Author: Chris Johnston <chris@thejohnstons.net>
Date:   Fri Dec 14 23:41:54 2018 -0800

    Update the Emoji API model to add User? attribute

Previously it was implemented under Discord.Net.Rest, which seems
inconsistent and unnecessary.

This also allows Commands docstrings to reference EmbedBuilder, since
Commands only has a dependency on Core.

* Added support for animated emoji

This was such a useful feature Discord, I'm glad you added this instead
of fixing bugs.

* Fix bugs in emote parser

* Added unit tests for emotes

* Add IEmbed#ToEmbedBuilder extension method

* Implementing reviewed changes.

* Switch to object initializers for author and footer.

* Add embed builder extensions

People in #dotnet_discord-net suggested that this should be part of
the lib after I demonstrated it

* Move some extensions into EmbedBuilder [2]

Apparently git didn't like that previous commit

* Fix error with EmbedBuilderExtensions

A summary of issues which happened:
- Git decided to add an amend commit (I told it to quit?)
- VS Code thinks everything is an error so it wasn't helpful
- dotnet decided to think there was no error until I deleted all
  build outputs and rebuild

Sometimes I question my ability to use version control properly.

Allows null embeds to be passed into ModifyAsync