FurStack v0.3.1

Changes:

1. fsams.lua was replaced with fsm.lua
2. MacOS support was added.
3. fsvm.lua and fsc.lua were rewritten.
4. fsvm was upgraded from 16-bits to 24-bits.
5. Iteration stack was added.
6. Data types are removed.
7. rand word was added for getting random numbers.
8. For loop was added. It's structured like this.

[iterator] [amount of iterations] loop
    [your code here]
for

9. *, /, >, >=, < and <= got unsigned version.
10. \0 escape sequence was added.
11. New stack manipulation operations were added. tuck, nip, crot, >i, i@ and i>