Implement Channel parent IDs

[Seklfreak]

The Discord API added a new field to the Channel object to support the newly added Channel Categories called parent_id. The change is mentioned here: https://discordapp.com/developers/docs/change-log#september-20-2017.

[Seklfreak]

Pull request: #448

[Hinara]

Need to implement the categories permissions too I suppose ^^

[Seklfreak]

Category Permissions should already be possible to change using ChannelPermissionSet, Categories are just Channels. Looking at the Diff for the Discord API Docs change, I think the only interesting addition would be to make it possible to set the parent_id using a func.
The commit in question: discord/discord-api-docs@7f0b113#diff-99b76a48d014c043f2f8804f6653ed82R353

[Seklfreak]

I'm not sure if we should break all previous versions by adding a parentID parameter to ChannelEdit or add a new func.

[Hinara]

I think it's better to create a ChannelEdit object like for messageEdit (Which will prevent problems with future changes as we only add fields). But the problem still the same.
@bwmarrin ?
And we need to take care of the new field permission_overwrites as they work with Category Channels if I understand correctly.
Ok didn't looked at the official docs for a while ^^' So yes apparently the only problem is about ChannelEdit.

[Seklfreak]

Just tested it and was able to change the overwrites using ChannelPermissionSet just as we used to do with Text and Voice channels. Internally there is no difference between Text, Voice and Category Channels.

[Hinara]

A bit too late I edit my post just few seconds earlier x)
Yes I wasn't understanding because if I correctly remember at a time permissions was named permissions.
So I was thinking permissionOverwrite was for Category Channels

[Seklfreak]

This has been completed in #493 .