Fix that way that NxWight UnitTests are reigistered as NSH builtin apps
Add NSRF42L01 driver.  From Laurent Latil
 Fix nRF24L01+ driver integration for the STM32 Tiny.  From Laurent Latil.
Add NRF24L01 terminal example.  From Laurent Latil.
Updates to README files
Move SAM3U header files to arch/arm/src/sam3u/chip. Some renaming of SAM3U to SAM to ssupport SAM4.  Convert all configs/sam3u-ek configurations to use the kconfig-frontends tool
Eliminated sam3u_internal.h. Use separate header files instead.  More renaming from sam3u_ to sam_ to make room in the namespce for the sam4l_
Add missing NSH configuration settings.  Correct some conditional logic for STM32 FALSH pre-fetch settings.  From Lorenz Meier
Rename sam3u/ architecture directories to sam34/ to include the SAM4L
Add dprintf() and vdprintf()
Fix an assertion
Add interrupt and memory map definitions for the AT91SAM4L
Add vector and chip cability definitions for the SAM4L family
Add a skeleton configuration that will eventually support the SAM4L Xplained Pro board
SAM4L alternate pin mapping header file; Use USART1 for virtual COM port console
NxWidgets::CImage: Allow NULL bitmaps.  From Petteri Aimonen
Change auto-increment timing in NxWidgets::CNumericEdit.  From Petteri Aimonen
NxWM::CTaskbar:  Add a method to redraw the task bar and the top application.  From Petteri Aimonen
Add stm32_dmacapable interface to determine is it is possible to perform DMA from a given address.
If CONFIG_STM32_DMACAPABLE is defined, use stm32_dmacapable to workaround attempt SPI DMAs from the CCM stack