16-bit demoscene example now works
Added a point
Changed write to print
Various changes

* Endless loop detection, drop "ret"
* Changed "write()" builtin function to "print()"
* Added "write" keyword for stosb/stosw
* Added ds register
* Improved register categorization function (8/16/32/64-bit)
* Fixed pushing "b" to stack for 16-bit
* Better handling of inline assembly with memory references