- Fixed indentation of VM code. Turned on stack checks for GCC only.
- Added new `VM_DISCARD` VM instruction (and compiler support). This makes the VM significantly more efficient.
- Configured Linux VM to be compatible with Apple II environment.
- Added line to force to interpret mode to prevent surprises.
- Compiler: fixed bug when exiting `for` loop using `return`. The compiler was leaking a word on the evalutation stack after jumping out of the body of the `for` loop.