[feature request] add "thank you"

[micwoj92]

What this would do, is just you type "!thank you @micwoj92" and the bot will respond with "@micwoj92 has been thanked x times"
It should be able to pick up @ and normal text (for example mastercoms) so you can avoid pinging
I think this would be a cool feature that would really show who is the best person on server. To prevent thank boosting, one user can thank only once every 24 hours. Pick your thanks wisely.
This requires a bit more than only a code:

1. A rule to post thank yous in thank channel should be enforced to make sure that the stats are fair and reflect the reality.

2. It shall work only in #thank so it will not be rigged by mastercoms by spamming "!thank you @mastercoms" 1000 times in private channel.