ChangeLog

	  warn() (and all variants vwarn(), llwarn(), etc.). (4) Debug
	  assertions can now be enabled separately from debug output. (5) You
	  can now enable subsystem/device driver debug output at different
	  output levels. For example, CONFIG_DEBUG_FS no longer enables file
	  system debug output. It enables general file system debug logic and
	  enables selection of CONFIG_DEBUG_FS_ERROR, CONFIG_DEBUG_FS_WARN,
	  and CONFIG_DEBUG_FS_INFO (2016-06-12).
	* strtoul() and strtoull():  Fix errno settings required by function
	  definition.  Resolved Bitbucket Issue #1. From Sebastien Lorquet
	  (2016-06-13)
	* arch/arm/src/stm32f7:  Add SPI driver.  DMA not yet supported.  From
	  David Sidrane (2016-06-14).
	* configs/nucleo-144:  Add test for STM32 F7 SPI.  From David Sidrane
	  (2016-06-14).
	* alert(): New debug macro: alert().  This is high priority,
	  unconditional output and is used to simplify and stanardize crash
	  error reporting(2016-06-14).
	* arch/arm/src/tiva: Bug Fix in tiva_serial.c - UART5, UART6 and UART7
	  were not being configured as TTYS0 for printing over serial console.
	  From Shirshak Sengupta (2016-06-14).
	* SAMV7: SPI: SPI-Freq. 40MHz; VARSELECT; hw-features
	  This change adds the following improvements:
	  - Increase the allowed SPI-Frequency from 20 to 40 MHz.
	  - Correct and rename the "VARSELECT" option
	    This option was included in the code as "CONFIG_SPI_VARSELECT" but
	    nowhere  defined in a Kconfig file. The change renames it to
	    "CONFIG_SAMV7_SPI_VARSELECT" and corrects the implementation
	    according the datasheet of Atmel. In short, this option switches
	    the processor from "fixed peripheral selection" (single device) to
	    "variable peripheral selection" (multiple devices on the bus).
	  - Add a new Function to the interface to control the timing and delays
	    of the chip according the ChipSelect lines. This function can
	    control the delay between the assertion of the ChipSelect and the
	    first bit, between the last bit and the de-assertion of the
	    ChipSelect and between two ChipSelects. This is needed to tune the
	    transfer according the specification of the connected devices.  
	  - Add three "hw-features" for the SAMV7, which controls the behavior
	    of the ChipSelect:
	    - force CS inactive after transfer: this forces a (short)
	      de-assertion of the CS after a transfer, even if more data is
	      available in time
	    - force CS active after transfer: this forces the CS to stay active
	      after a transfer, even if the chip runs out of data.
	      Btw.: this is a prerequisit to make the LASTXFER bit working at all.
	    - escape LASTXFER: this suppresses the LASTXFER bit at the end of the
	      next transfer. The "escape"-Flag is reset automatically.
	  From Frank Benkert (2016-06-14)