Sempahores:  Add logic to clean up after task_delete() or pthread_cancel() if the task happens to be waiting on a semaphore when it is cancelled

device, while it is being terminated by pthread_cancel(), then
uart_close() gets called, but the semaphore (dev->recv.sem in the above
example) is still blocked.

This means that once the serial device is opened next time, data will
arrive on the serial port (and driver interrupts handled as normal), but
the received characters never arrive in the reader thread.

This patch addresses the problem by re-initializing the semaphores on the
last uart_close() on the device.

STM32 OTG HS DEV (in FS mode): Disable ULPI clock enable in RCC AHB1 Register.  If Both ULPI and the FS clock enable bits are set in FS mode, then the ARM never awakens froom WFI due to a chip issue.  From Ken Pettit

Tiva I2C: Don't try to ACK and STOP on the same byte.  Improve logic that suppresses STOP on a repeated start

strncpy: Commit d0c76ccacf0dc8988f9617ad82bf4349f456bb08 will trash a lot of memory if n == 0.  From Hiro

Lots of fonts that derive from X11-misc-fixed-* fonts.  Converted for use by NuttX by Pierre-Noel Bouteville

TM4C123G LaunchPad:  Add initialization logic for an external AT24 EEPROM.  This is intended only to suppport testing of the Tiva I2C driver