kernel: add free page system call

kernel: reserve first 16 pages of a service to make accidental Null pointer resolutions thorw an exception

kernel: fix compiler warning about invalid pointer conversion

add mouse service to manage mouse position

add fork system call

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

usb xhci: send configure endpoint command to set up endpoints

xhci: clean up slot initialization

fix weird problems with getPhysicalAddress system call

create async xhci command function using events

fix problem where page fault happens because not the whole string is mapped in a insertString system call

add sleep function to PIT driver

receive xhci events

fix issue #1: ELF files not loaded correctly

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

print basic XHCI information

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

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 kernel events ...

kernel events get triggered by the kernel when certain things happen.
first example: log a message whenever a new programm is loaded from the initrd

add an additional argument to request calls

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

mov syscall handlers to different files