using sti in syscalls, remove a bunch of old imports and code, move
keyboard scancode handling to keyboard.rs, add a new KeyboardEvent based
layout where press/release and unicode is handled, add a kbd_read
syscall which writes kbd events to a userspace buffer, add a usercopy
file which provides safe copying functions to userspace
relocations, add some more functions to libxunil, use include inside of
tests instead of manually defining types and add basic libc header
files. Move libxunil to the user folder, and add helloworld and
doomgeneric as apps
