Started using tuples for coordinate storage

They make possible to iterate throught the values with a 'for', working as nicier arrays.
Revert "Started using tuples for coordinate storage"

On the current version of nimrod is impossible to iterate over two tuples of different types at the same time. Arrays seems to be the working choice.

This reverts commit 63581148031888bb966eff51a3b2532c07456233.
Three element arrays for points and related refactoring

Lots and lots of refactoring making the code shorter and less repetitive (no more copy-pastying programming). Instead of x, y, z we have three element arrays indexed by an enum.

Also refactored vertex creation. The previous function pair had implicit call order, magic values, etc, and was long. It also took many lines of calling to do work.
Moved variable creation out of loop in renderPts

Maybe a performance win, maybe it was already optimized by the compiler. One more line because of this, but I removed a blank line to even out.