Conflicting username impementations

[KaydaCant]

Usernames were already implemented in #195 , but were reimplemented in #170 . Usernames are still updated by username.txt and the launch options username is ignored.

[void2012]

@simulpingus, @lspepinho

[LexLeethor]

i have a felling this is gonna happen alot

[codeHusky]

This is now fixed. We support username.txt as well as the -name launch argument.