P23: Adding the problem statement.
P23: Got the solution correct after a couple 'first tries'.  I have both a bitmap and array way of tracking the numbers that could be expressed as the sum of two abundant numbers.  But, for simplicity, I'm relying on the array.  Over all, this solution is pretty poor performance wise.  Takes a couple seconds to run.
Merging problem 23 ('P23') branch into master.