Mark3 RTOS Source

-Initial checkin of platform support for ARM Cortex-M0 parts, targetting stm32f0/GCC (since that's the board I have). Toolchain is working - code gets generated, libraries get built.
-Kernel port for CM0, however, is just a stub at this point, need to implement NVIC code for SysTick timer, as well as the gross inline-assembly for context switching.
-There's no board-specific init code tied into Mark3, so that would need to be linked in as well for any example code. Really, example code will have to be abstracted out by platform going forward
-Fixed some default usage of K_UCHAR arrays as the stack - Implemented new K_WORD type for platform-specific register word-width.

Adding DCPU assembler file for "hello world" to the DCPU examples folder

-Adding DCPU emulator "hello world" example
-Also, replacing all tabs with 4 spaces

Fixed a couple of bugs in the DCPU VM core
-Wrong operand used in JSR opcode, causing incorrect jumps
-Incorrect stack pointer pre/postincrement operators in push/pop

Removing the previous uart driver directory - which is causing the 644/1284p/1280 ports from working properly

Fixing the SWI code in the 1280 port.

Adding preliminary atmega1280 support... context switching should be OK

Adding automated unit testing script for running the test code on a connected Arduino board running the Mark3 bootloader

-Fixed up some documentation and functionality related to the timer-tolerance feature
-Fixed the semaphore unit test
-Adding python script used to automate the execution of unit tests under simavr

Added "tolerant" timers, allowing for improved interrupt performance (i.e. better power management due to fewer interrupts/CPU wakeups)