Leveling System

The whole leveling system has been reworked. Here are the highlighted changes:

New: /xp has been reworked and renamed to /adjust.
New: Use /xp to change the XP rate of a server. (mods only)
Maximum level increased from 60 to 70.
XP requirements for each level from 1 to 70 have been changed.
Users will no longer get random amount of XP. Instead, they will receive a specific amount of XP which will scale based on their level.
/roll XP cooldown has been reduced from 30 to 10 sec.
Messages and interactions XP now have a 10 sec cooldown to avoid spamming.
Voice channel XP will no longer be granted whenever a user leaves a voice channel. Users will now receive voice channel XP every 20 mins as long as they are in a voice channel.
/leaderboard has been updated and fixed.
Leveling profiles of users who leave the server will now be removed from the database.

Music System

/favorite play will now skip the tracks which the player is not able to play.
Fixed a bug that could cause a problem when 2 tracks are added to the queue at the same time.
/filter will not be available if the current track is longer than 10 mins.
Some new player error handlers have been implanted.

"Reason" field has been added to warning system for more clarity. Every warning activity includes a reason now and the reason will be sent to the warned user, too.
/warn has been updated and now has a "reason" option.

New: Use /set to configure a specific channel for each event. (mods only)
/system has been removed and merged with /info. /info also shows specific channels of each event.
/setwelcome has been removed.

New: Use /blackjack to play a round of blackjack with SayehBot. Users will win or lose XP by playing this game.
/finger has been renamed to /flip.
/commands has been updated to show the commands sorted alphabetically. (Ascending)
Bookmark button and favorite view buttons are now usable for multiple times.
Stream notification is now expected to not keep updating the message when there is no need to. (closes #7)
Fixed a bug with birthday announcements which could show the age of the user incorrectly.
Some embed footers have been removed for more clarity.
Nonmusical interactions will no longer be removed. They will be deleted only if the process was unsuccessful.