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

use sleep function for xhci driver waiting for the controller to start

add sleep function to PIT driver

try initializing xhci hub

add system call to retrieve the physical location of a virutal address

add lspci user programm

move 'gets'-functionality to ioManager to simplify the shell source code

add await syscall

check if a message should be printed to the main vga screen by checking if any syscall in the 'syscall stack' is the foreground process

remove old log function, make \n mandatory for printing a new line

route the shell service to the vga output

rewrite general IO using an IO-manager

add system call to look up the names of functions

add basic stack tracing ability

rename service proivder to service function ...

now matches the documentation in the wiki

add formating print function

make malloc functions accessible to user mode programs

log to vga display

add system call to request memory ...

print hi to vga screen

use string identifiers for events ...

(some rework of the string saving system was required)

use stringmap for communication between processes

use saved strings for service interaction system calls

add discard string system call

add read string syscall

add stringmap insert and read length functions

seperate log into log file and a parallel driver

add events

add a static libary and fix interrupts

enable subscribing to an interrupt and set up the PIC

enable interrupts