libc: removing newlib, adding BSD libc
posixcompat: moving gettimeofday to libc
harness: adding a simple math test
lwip, lwip2: moving includes to /include, compiling with BSD headers

Signed-off-by: Adam Turowski <adam.turowski@inf.ethz.ch>

Added header termios.h, sys/_termios.h and sys/ttycom.h from FreeBSD. Removed
the stub header in sys/termios.h.

POSIX requires the header termios.h to lie in the base include directory not
under sys/. FreeBSD spilts this header into three termios.h, sys/_termios.h and
sys/ttycom.h.

This header files are required by openssh.