Simulatin:  Save the intial terminal mode and restore this before terminating.  Otherwise, the NSH shutdown command leaves the console in raw mode

sim configuration: Add support for board_app_initialize() which is needed when CONFIG_LIB_BOARDCTL=y

Implement WNOHANG for waitpid() only and for the case of CONFIG_SCHED_HAVE_PARENT not selected.  From Max Neklyudov.

STMPE811: I found that, in stmpe811_instanciate(), when CONFIG_STMPE811_MULTIPLE is enabled, and the call to stmpe811_checkid() fails, then the linked device list is not restored to its previous state.  From Sebastien Lorquet.

drivers/net/slip.c:  Fix a missed name change when many of network interface names changed sometime back but were apparently never updated for SLIP

include/nuttx/net/netconfig.h:  Fix some backward compilation that was emitting #error in the wrong condition when SLIP was enabled

Fix a Cortex-A compilation error in the vfork() logic when system calls are enabled in modes other than CONFIG_BUILD_KERNEL.