Refactor

Update build environment to use a common Makefile rather than a
new file for each problem solution. Master executable handles
running the correct solution function based on command-line
arguments.

Redirected build outputs (*.o) files, to a new obj directory.
Refactor

Migrated the problem 009 solution from the old format into the new
unified executable.

Moved the function pointer table into the ProbjectEulerSolutions.hpp
file instead of in "main" since it is specific to the solutions.
Bug Fix

Addressed error in the Problem001 solution; increment by i, not
by just 1...
Adding Solution

Migrating the Problem011 solution from the old way to the new
way. Still works and generates the correct answer.