SAMA5 clock configuration should now agree with Atmel sample code; Added header file with macros to enable and disable peripheral clocking

SAMA5/Cortex-A: Improve irqsave/restore inlines + add irqenable.  Add skeleton file for SAMA5 interrupt management.  Also change from last commit that was left in the editor

Add an NSH configuration for the Arduino Due; Pluse several fixes related to the Due and to the SAM3X in general

Arduino Due: Fixes to FLASH address, flash wait states, updated Comments.  Now boots and runs a bit before crashing

Flesh out the Arduino Due board configuratino and integrate it with the build and configuration system

Add peripheral configuration logic for the SAM3X/3A; Change all references to SAM3/4 SPI to SPI0 for compatibity with the SAM3X/3A which has SPI0 and SPI1; Add directory which will eventually holdl an Arduino Due port

Add support for a separate CCM memory allocator for members of the STM32 family that support CCM memory

Straighten out issues about who calls C++ initializers with CXXTEST or HELLOXX are built as NSH applications; Add an ofstream test to CXXTEST suggested by Michael; Update many defconfig fiels to that they set configurations to handle C++ constructors just as before these configuration changes