Revert Previous changes in order to switch master to "new" branch.
v063 - Giacomo
Linux make update.
Update linux build system, default non-multithreaded lib.
Change funcs to all use local context instead of global.  Allows more than one runtime.

Conflicts:
	examples/pc/main.c
	examples/pc/pclib.h
	sbi/funclib.h
	sbi/sbi.c
	sbi/sbi.h
Fix non threaded program counter.
Fix linux examples. - TODO interrupts.
Update mt code
Remove debugging delay from Linux mt demo.
Move all thread specific functions to internal api.
Standardize public api.
update linux_mt/linux example programs.

This update is the beginings of supporting a thread instruction and having the interpreter automatically start a new thread.
Cleanup API.
Also cleaned code up a bit.
Separate instructions to use common header file. Clean sbi.h up a bit.
Added thread instruction.
Removed concept of individual thread streams.
Moved labels and variables to global scope.
Implement removing threads.
Add counter for return addresses.
if a thread encounters a return and there
is no more return addresses, the thread will end.
Fix stack overflow in sasmc error handler.
Introduce concept of threadid for each thread.
Introduce concept of wait for a thread.
Introduce push/pop and thread local stack.
Introduce register concept for thread local variables.
Add support for hex numbers in value fields.