Fixed channel mode keystrokes for consistency & not clash.
- ⌘⌥M is reserved for "Minimize All."
- New bindings are as follows:
  - Moderated (+m) is now ^⇧⌘M
  - Unmoderated (-m) is now ^⌘M
  - Invite Only (+i) is now ^⇧⌘I
  - Anyone Can Join (-i) is now ^⌘I
Application name is _not_ "Textual & IRC" :)
Merge branch 'master' of ssh://gh/winny-/Textual