Add !timeout command

[navarr]

Acceptance Criteria

• I can type !timeout 15 @Navarr#0001 Being a jerk and Navarr#0001 will be muted for 15 minutes
• 5 minutes after such a command is typed, I restart the bot. 15 minutes after such a command, Navarr#001 is unmuted.
• For the time, I can specify multiple numbers and letters in one string: (3d2h5m)
  • m - Minutes
  • h - Hours
  • d - Days
• If a user is timed out that is already muted, I am messaged a warning that I cannot time them out b/c they are already muted
• If a user is already timed out and I type the command, the new timeout overrides the old one, and I see a message saying how long they had left on their previous timeout and how long they have left on their new one

[JamsheedMistri]

Could we alias this to tempmute?