Improved Guild#createChannel, added RoleResolvable and fixed a bit of Emoji stuff (#1754)

* Made creating channels with overwrites nicer
and added ClientDataResolver#resolveRole

* Renamed ChannelPermissionOverwrites to ChannelCreationOverwrites

* Added RoleResolvables everywhere possible

* Fixed Emoji#setName resetting restricted roles and Emoji#equals

Which will lead to emojis not to update when roles are being added removed.

src/client/ClientDataResolver.js

@@ -8,6 +8,7 @@ const Message = require('../structures/Message');
 const Guild = require('../structures/Guild');
 const Channel = require('../structures/Channel');
 const GuildMember = require('../structures/GuildMember');
+const Role = require('../structures/Role');
 const Emoji = require('../structures/Emoji');
 const ReactionEmoji = require('../structures/ReactionEmoji');
 const { Error, TypeError } = require('../errors');
@@ -101,6 +102,27 @@ class ClientDataResolver {
     return guild.members.get(user.id) || null;
   }
 
+  /**
+   * Data that can be resolved to a Role object. This can be:
+   * * A Role
+   * * A Snowflake
+   * @typedef {Role|Snowflake} RoleResolvable
+   */
+
+  /**
+    * Resolves a RoleResolvable to a Role object.
+    * @param {GuildResolvable} guild The guild that this role is part of
+    * @param {RoleResolvable} role The role resolvable to resolve
+    * @returns {?Role}
+    */
+  resolveRole(guild, role) {
+    if (role instanceof Role) return role;
+    guild = this.resolveGuild(guild);
+    if (!guild) return null;
+    if (typeof role === 'string') return guild.roles.get(role);
+    return null;
+  }
+
   /**
    * Data that can be resolved to give a Channel object. This can be:
    * * A Channel object