USB host: If the implementation of the disconnect method frees the EP0 endpoint, then it must nullify it in the port structure

STM32 USB device.  Add protection in the event that out-of-bound enpoint numbers are received.  From David Sidrane.

USB host:  Need to include the port structure when disconnecting, otherwise may destroy a root hub port

LPC17 GPIO:  Reorder steps when an output GPIO is configured in order to avoid transient bad values from being output.  From Hal Glenn.

SAM PIO: sam_pio.h needs to include chip/sam_memorymap.h in order to resolve some conditional logic properly

Added missing EXTI definitions for the STM32 F3; Correct an error the port D base address in the STM32 F3 and F37 memory maps.  From Greg Meiste.

STM32F4-Discovery: Part of logic to initialize the ELF loaded in the board startup logic.  From Leo aloe3132

binfmt: Fix a debug statement that does not have the correct number of arguments.  From Leo aloe3132

EFM32 USB host: Add missing trace data and some missing connection-related logic; update a configuration

STM32F429i-Disco: Add some missing USB host configureation.  Fix some some duplicate class registration that causes infinite loops in USB registry searches

USB hub:  Add a configuration option to fallback to polling mode if the the HCD async method does not work.  Don't call DRVR_CANCEL twice, and certainly not from the interrupt level.  Add so checks so that we do not do some normal asynchronous actions if the hub has been disconnected

STM32F4-Discovery: Add configuration option to select the size of the stack used with the usbhost waiter.  Needs to be bigger when a hub is supported