add basic support of an UART device
add missing list of pciids
add missing copyright statement
cosmetic changes
add missing header
add mailbox system
create task to handle incoming messages
improve some comments
remove typo
add Daniel to the author list
preperation to support memory mapped io
minor modifications in atomic_int32_inc/_dec

=> now, the functions returns also the current counter
add new function to determin if a device supports MMIO
reduce the number of debug messages
add function to detect processor features
redesign of the IO interface

- all messages are stored in a ring buffer
- new devices (e.g. UART) are able to print previous messages
remove typo in a comment
some cleanup
use flag PG_GLOBAL to map the video memory
add helper functions to determine if the pci device use MMIO or IO ports