Voice Send Support

The highlight of this release is fully-working voice transmission support, with many features and bug-fixes laying in the backdrop.

Features

• Add voice transmission support, with multiple builtin classes for streaming music using youtube-dl, ffmpeg, etc
• Add support for opening DMs with users
• Support loading bot level getter function from a module/function path
• Add Plugin.wait_for_event, which waits for a specified event (and filters on it), useful for reaction interactions
• Add support for updating managed emojis
• Add support for modifying guild members
• Add Message.get_reactors for fetching a list of all reactors for a given emoji
• Better avatar support, incl. for users w/o avatars
• Upgraded various dependencies

Bug Fixes

• Fix commands being strictly case-sensitive
• Fix command edit detection triggering on embed updates
• Fix some information being smashed upon GUILD_UPDATE's
• Fix state handling of VOICE_STATE_UPDATE
• Fix emojis losing their guild_id after being updated
• Fix some obscure typing issues
• Fix bulk message deletion
• Fix GuildMember.remove_role
• Fix MessageEmbed.set_footer