#5 allow users to create new variables

[Brian Fegler]

there will be 2 ways to define them

define(x,...)
x=....

need a another function in VariableTable called
setVariable(string, object) and a few other methods.

everything else should be done internal to the
VariableTable class

need away to keep the decimal place correct for
variables maybe a setContext or another parameter? if
decimal place is set to 50, you have a variable in
there, then you change the allowable decimal place to
10, then back to 50, what will you have?