usb refactoring: generalize abstraction to search for descriptors

pit refactoring: use event code

usb refactoring: remove temporary caching of usb devices

usb refactoring: split up setup endpoints functions

usb refactoring: add direction parameter to usb command

usb refactoring: pass endpoint index in device ID

usb refactoring: use single command function

usb: remove redundant check for pci enumeration

usb: add abstraction for set protocol and set idle

refactor usb: abstraction for normal packet

add hid program to manage HID (usb) devices

add mouse service to manage mouse position

avoid creating a new service if one already exists

add fork system call

kernel await / fire event: add code to wait for specific event

usb mouse: report summed position

stdio: add negative sigh for printing negative numbers

fix compiler errors (shift count overflow)

usb xhci: continously print mouse report data

usb xhci: initiate interrupt IN transfer

usb xhci: send configure endpoint command to set up endpoints

usb: show configuration and interface information

usb: hlib: use "unsafe" direct event calls to work without strings

usb refactoring: no more xhci-specific code in main usb.h file

usb : print usb version

shell: don't even try to create a "" program without a name

xhci refactoring: sperate out all xhci-related code to its own directory

xhci: refactoring: move out xhci controller code

make printf function available for not-main userland files

xhci: refactoring: use SlotXHCI instead of long parameter list