WIP (won't compile now): add process, scheduler and all the things
Merge branch 'master' into multitasking
rename systick clock source constants
rename common/drivers to common/common_drivers to avoid ambiguous includes
Merge branch 'master' into multitasking
cleanup: add common ALIGN() macro
multitasking: It compiles! Let's ship it! :D

For your own safety, do not read the code right now. I will clean it up soon.
make current_process public; add 3rd program to `leds`
clean up some of yesterday's mess :D
update README (well, parts of :D)