Remove some OS test configurations.  These don't have much value after the initial bring-up (and are certainly not worth converting to kconfig-frontends tools).

Set CONFIG_DEFAULT_SMALL=y in the defconfig for all smaller MCUs so that if they are reconfigured, they will pick up the most conservative options for all new settings

configs/*/defconfig:  If CONFIG_NSH_LIBRARY is set, make sure that CONFIG_NSH_READLINE is also set or the configuration will use the CLE the next time it is reconfigured

procfs:  Remove newline from the end of the cpuload and loadavg outputs so that the returned percentages can be printed on the same line as other data.

SAM4E:  Completes all SAM4E register definition header files.  Also a SAMA5D3 ADc register definition fix

networking: Fix one place where the reference count was not being zeroed.  This is really a cosmetic fix UNLESS CONFIG_DEBUG_NET is enabled, then it causes assertions

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.