fix race condition in mutex release
Merge pull request #19 from plawatsch/master

fix race condition in mutex release
removed old workaround yields
removed ~50 lines in boot.s
removed another 20 lines from boot.s
removed an old comment
removed another comment
Merge branch 'next_year_improvements' into next_year_devel

Conflicts:
	arch/x86/32/source/boot.s
fix for compiling arm on ubuntu with gcc-4.9
split allocating and initialising a kernel thread info into two pieces
fix makro, always wrap parameters in ()
add US_BACKTRACE debug flag
refactor out stabs info into their own object (builds break now)
the kernel now has it's own instance of debug symbols
split thread info creation/allocation also for x86-32
prettyfiy register printing
loader can now load userspace debug symbols (if so requested).
it's not possible to pagefault / load on demand since they are not in
a loadable section in elf
add option to load debug symbols in a user process
default to on
add stack unwinding for userspace threads
a thread can print it's userspace backtrace
add function to the scheduler that will print backtraces
for all threads currently in userspace