%groups v9.1.1

This release introduces better message scrolling behavior, resolves problems with group notifications and thread displays, and fixes image uploads and YouTube embeds. We've also addressed various cosmetic and performance issues.

• Removes the "Log Out" button (which did nothing).
• Removes erroneously-uploaded images (base64-encoded) from channel history.
• Fixes an issue where sending a message would not scroll the Chat channel or DM window down.
• Fixes an issue where pending posts inside of threads would briefly appear in the main channel until sent.
• Fixes an issue where people joining or leaving a group would cause the group to jump to the top of the Home sidebar despite there being no unread items.
• Fixes an issue where personal Lure invitations would not initially refresh the landing page with users' existing nicknames.
• Fixes an issue where images would upload without a file extension, occasionally preventing download on mobile.
• Fixes a cosmetic issue with the personal invitation link popover.
• Fixes size and placement issues with YouTube embeds.
• Fixes an issue where group creation would be slow the first time after re-compile.