[BUG] Sorting of usernames is case-sensitive

[soundstorm]

Usernames can be chosen as mixed case strings, which results in an order of usernames like following (sidebar):
A
B
C
a
b
c

They should be up or downcasted before sorting.

[graywolf336]

This is because we use JavaScript's default sort: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort

[rafaelks]

This is causing this weird sorting.