Updated ListOps.hs

Added a function groupsOf :: Int -> [a] -> [[a]]
Takes a list and seperates it into groups of size n
Added RPN.hs

Added an evaluator for reverse polish notation
Added RoadSystems.hs

Added a module to solve road systems as defined in
http://learnyouahaskell.com/functionally-solving-problems
Added paths.txt

The paths from http://learnyouahaskell.com/functionally-solving-problems
Added Symbols.hs

Started work on a symbolic math module
Recompiled ListOps.hs
Updated TreeGameBackend.hs, persistentTreeGame.hs

Cleaned up and modularized code, allowed you to choose which file you
open for the tree
Compiled persistentTreeGame.hs, TreeGameBackend.hs