uPOSIX v0.0.1

This is the first pre-release of uPOSIX. It contains basic functionality, some device drivers and examples. It's not fully tested.

Peripherals access with open, read, write, close and ioctl functions.
Inter-thread communications using pipes (pipe, read, write).
Pthreads functions:
pthread_create
pthread_join
pthread_setschedparam
pthread_getschedparam
pthread_mutex_init
pthread_mutex_destroy
pthread_mutex_lock
pthread_mutex_trylock
pthread_mutex_unlock
pthread_exit
usleep
sched_yield