SAM4E: Update SAM3/4 GPBR, HSMCI, PWM, RSTC, RTC, RTT, SMC, and WDT register definition header files

ARMv6-M/ARMv7-M: Correct a register handling error in signal delivery (Kernel build mode only).  Noted by Mike Smith.

Comment out all CONFIG_APPS_DIR settings in all defconfig files.  We con't know where the apps/ dir will be be until install time

Add CONFIG_DEFAULT_SMALL that will select default values for configuration settings based upon either more features or smaller footprint.  Turns out not be be useful for modifying existing defconfig files because the defaults do not apply in that case

unlink/rm can now be used on nodes in the pseudo-filesystem.  There is new configuration option to suppress these costly and mostly useless operations on the pseudo-filesystem

Olimex LPC1766STK: FTPC configure changed to use the kconfig-fronteds tools by Alan Carvalho de Assis

SAMD20: Changes for clean build of SPI driver and SAMD20 Xplained Pro board with the I/O1 module installed