PIC32MZ: Fix some repeated typos and work around an issue with passing defined parameters to a macro that takes multiple parameters

PIC32MX/Z: Partial review of PIC32MZ cp0 register -- need to do more; Also found issues with definitions for PIC32MX -- need to be retested

PIC32MZ: Add file for GPIO interrupt support.  There are issues so configuration is EXPERIMENTAL for now

PIC32MZ: Add beginnings of CPU initialization logic.  Still some bad logic for setting up peripheral clocking

PIC32MZ: Make sure that the microMIPS ISA is selected on all common MIPS32 assembly files when the PIC21MZ is selected

MIPS:  Add some build support for the M14K and also for the PIC32MZ Starter Kit.  Still a long way to go

STM32: Fix for compilation introduced by last backup RAM change.  Not sure it it is correct, be now things do compile