* add missing $(AD) to osx $(LINK) invocation
* move osx build determination to native makefile
* move old libc test to native makefile
* set objcopy to "true" - it is superfluous for native no matter what the system is
* add some documentation to natives makefile
wrap some libc functions that do system calls (terminal output)
wrap read/write with syscall guard
define real_read/write (next dynamic linker find for read/write)
guard system calls in remaining code
introduce native_internhal.h
throw out some debug statements that break things
clean up includes a bit
declare board_init in native_internhal.h
add -ldl to LINKFLAGS for cpu/syscalls