SSTNPL: tables and iterators

SSTNPL is already a handy language for basic mathematics, and with these 2 new features, it just got a whole lot more capable.

Tables:

SSTNPL now features a 2-axis static-size table system with data read-write.
The actual algorithms used are based on work of a nifty new SSTNPL-based maze engine now available in 'APPS' directory in SBTCVM Gen 2's repository.

• read and write values with ease. (especially when paired with the other new SSTNPL feature mentioned below.)
• special macro read instructions for printing characters, ternary and decimal values.
• both raw-string and general data value table rows.

https://github.com/SBTCVM/SBTCVM-Gen2-9/blob/master/textdocs/SSTNPL/tables.txt

Iterators:

two handy iterator instructions. The main inspiration here is wanting an easy way to work with the new tables linearly, without winding up with insanely complex iterator code like what happened with that maze engine i mentioned above.

uiter & diter can iterate over a given range of integers (uiter going up from start to end,  and diter going down from start to end)

https://github.com/SBTCVM/SBTCVM-Gen2-9/blob/master/textdocs/SSTNPL/iterate.txt