Add freedom-kl25z/minnsh configuration:  This is an experiment to see just how small we and get an NSH configuration.  From Alan Carvalho de Assis.

KL25Z:  Add low-level up_lowgetc function that can be used to provide an NSH console when the file system (and hence the serial driver) is disabled.  From Alan Carvalho de Assis

KL25Z:  Add low-level up_lowgetc function that can be used to provide an NSH console when the file system (and hence the serial driver) is disabled.  From Alan Carvalho de Assis

The last checkin replaced some impossible error handling with DEBUGASSERT.  Except that one of the case is actually possible in one cornercase and had to be restored

OS startup logic should not call group_setupidelfiles() if there is no file system support configured

Networking:  Fix backward conditional in test to see if address is in ARP table.  From Max Holtzberg

Networking: If sending out of the subnet, device lookup by IP will fail.  Fall back to ETH0 for now.  From Max Holtzberg

SAMA5 GMAC:  Initial driver check-in is just the EMAC driver forced to compile with the GMAC register definitions

Mov apps/examples/composite to apps/system/composite; convert configs/stm3210e-eval/composite to use kconfig-frontend tools -- untested

SAMA5 EMAC:  Need to pace RX and TX because and RX can result in a TX; Process TX interrupt events before TX interrupt events for the same reason

SAMA5 EMAC: Add some need D-Cache Flush/Invalidate operations.  Add support for CONFIG_NET_DUMPPACKET

Move CONFIG_NET_DUMPPACKET from LPC17 and STM32 to commong network drivers.  Automatically enabled CONFIG_NETDEVICES when any Ethernet driver is enabled

Move CONFIG_NET_DUMPPACKET from LPC17 and STM32 to commong network drivers.  Automatically enabled CONFIG_NETDEVICES when any Ethernet driver is enabled